| 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:CommonStockValue | ▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▄▄▄▄▄▄▇▇▇▇▇▇█████▇▇▇▇▇▇▇ | 8.8 | 1.7 | 18.2 | 15.5 | 6.1 | 0.0 | 0.0 | 0.0 | 2.9 | 0.0 | 0.0 | 11.5 | 6.0 | 0.0 | 7.3 | 0.0 | 0.0 | 113.2 | 116.5 | 130.7 | 123.8 | 133.4 | 134.026 | 271.116 | 265.645 | 262.967 | 262.28 | 246.001 | 243.618 | 296.492 | 295.955 | 294.037 | 287.978 | 283.496 | 274.709 | 274.622 | 271.841 | 267.597 | 260.199 | 259.336 | 257.623 | NA | 236.503 | NA | NA |
| us-gaap:SharesOutstanding us-gaap:StatementEquityComponents us-gaap:CommonStock | ▇▇████████████▁ | 38.5 | 38.5 | 39.5 | 39.5 | 39.4 | 39.4 | 39.7 | 39.9 | 40.0 | 40.2 | 40.4 | 40.7 | 40.7 | 40.6 | 15.4 | NA | NA | NA | 16.5 | NA | NA | NA | 16.6 | NA | NA | NA | 17.472 | NA | NA | NA | 17.948 | NA | NA | NA | 17.448 | NA | NA | NA | 17.178 | NA | NA | NA | 16.571 | NA | NA |
| us-gaap:CommonStockSharesIssued | NA | NA | 39.5 | NA | NA | NA | 39.7 | 39.9 | 40.0 | 40.2 | 40.4 | 13.6 | 13.6 | 16.5 | 15.4 | 15.4 | 16.5 | 16.5 | 16.5 | 16.6 | 16.6 | 16.7 | 16.6 | 17.569 | 17.58 | 17.581 | 17.472 | 17.322 | 17.292 | 17.857 | 17.948 | 17.977 | 17.925 | 17.964 | 17.448 | 17.461 | 0.017403 | 17.347 | 17.178 | 17.166 | 17.15 | NA | 16.571 | NA | NA | |
| us-gaap:CommonStockSharesOutstanding | NA | NA | 39.5 | NA | NA | NA | 39.7 | 39.9 | 40.0 | 40.2 | 40.4 | NA | NA | NA | 15.4 | NA | NA | NA | 16.5 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding | ▁█ | 39.3 | 39.6 | NA | 40.1 | 39.5 | 39.7 | NA | 40.7 | 40.7 | 40.6 | NA | 13.7 | 13.6 | 14.5 | NA | 15.5 | 16.3 | 16.8 | NA | 16.9 | 17.0 | 17.0 | NA | 17.769 | 17.735 | 17.268 | NA | 17.303 | 17.88 | 17.419 | NA | 17.955 | 17.921 | 17.828 | NA | 17.575 | 17.502 | 17.433 | NA | 16.974 | 16.935 | 16.358 | NA | 16.768 | 14.895 |
| us-gaap:WeightedAverageNumberOfSharesOutstandingBasic | ▁█ | 38.7 | 39.0 | NA | 39.5 | 39.5 | 39.7 | NA | 40.0 | 40.1 | 40.4 | NA | 13.6 | 13.5 | 14.4 | NA | 15.3 | 16.1 | 16.3 | NA | 16.4 | 16.5 | 16.5 | NA | 17.347 | 17.331 | 17.268 | NA | 17.02 | 17.531 | 17.419 | NA | 17.328 | 17.268 | 17.209 | NA | 17.13 | 16.978 | 16.903 | NA | 16.858 | 16.444 | 16.358 | NA | 16.311 | 14.44 |
| us-gaap:EarningsPerShareBasic | █████▁███████████████████████████████████████ | 2.8 | 0.93 | 0.43 | 1.09 | -3.0 | -590000.0 | 0.1 | 0.37 | 2.66 | 0.29 | 0.28 | 4.15 | 7.6 | 12.61 | 2.5 | 1.09 | 4.86 | 0.44 | 1.62 | 0.52 | 4.16 | 0.17 | 0.44 | 0.24 | 3.12 | -0.09 | -0.81 | 0.21 | 3.23 | -0.04 | -0.31999999999999984 | 0.52 | 2.85 | 0.06 | 0.1499999999999999 | 0.34 | 2.82 | 0.08 | 0.4299999999999997 | 1.17 | 2.39 | -0.19 | -0.1399999999999999 | -0.04 | 1.85 |
| us-gaap:EarningsPerShareDiluted | █████▁███████████████████████████████████████ | 2.76 | 0.91 | 0.43 | 1.08 | -3.0 | -590000.0 | 0.1 | 0.36 | 2.63 | 0.29 | 0.28 | 4.12 | 7.55 | 12.55 | 2.46 | 1.08 | 4.81 | 0.44 | 1.6 | 0.52 | 4.11 | 0.16 | 0.43 | 0.24 | 3.1 | -0.09 | -0.81 | 0.2 | 3.21 | -0.04 | -0.33000000000000007 | 0.52 | 2.81 | 0.06 | 0.13999999999999968 | 0.34 | 2.77 | 0.08 | 0.4099999999999997 | 1.17 | 2.37 | -0.19 | -0.1499999999999999 | -0.04 | 1.85 |
| us-gaap:IncomeLossFromContinuingOperationsPerBasicShare | █████▁████████████████ | 2.8e-06 | 9.300000000000001e-07 | 4.1e-07 | 1.0900000000000002e-06 | -5.9e-07 | -0.57 | 1.1e-07 | 3.8e-07 | 2.69e-06 | 3e-07 | 1.8e-07 | 4.27e-06 | 7.61e-06 | 9.8e-07 | 2.25e-06 | 8.5e-07 | 4.52e-06 | 1.3e-07 | 1.17e-06 | 2.0000000000000002e-07 | 3.97e-06 | 4.3e-07 | NA | NA | NA | NA | NA | NA | NA | NA | -3.0000000000000025e-07 | 5.2e-07 | NA | NA | 1.4999999999999991e-07 | 3.4000000000000003e-07 | 2.8199999999999997e-06 | NA | 2.3e-07 | 1.17e-06 | 2.38e-06 | NA | -2.9000000000000003e-07 | 2.2e-07 | 1.8999999999999998e-06 |
| us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare | █████▁████████████████ | 2.76e-06 | 9.100000000000001e-07 | 4.1e-07 | 1.08e-06 | -5.9e-07 | -0.57 | 1.1e-07 | 3.7e-07 | 2.66e-06 | 3e-07 | 1.8e-07 | 4.24e-06 | 7.57e-06 | 9.7e-07 | 2.2200000000000003e-06 | 8.4e-07 | 4.4699999999999996e-06 | 1.3e-07 | 1.16e-06 | 2.0000000000000002e-07 | 3.9300000000000005e-06 | 4.2e-07 | NA | NA | NA | NA | -7.599999999999998e-07 | 2.0000000000000002e-07 | NA | NA | -3.1000000000000005e-07 | 5.1e-07 | NA | NA | 1.399999999999997e-07 | 3.4000000000000003e-07 | 2.77e-06 | NA | 2.0999999999999997e-07 | 1.16e-06 | 2.36e-06 | NA | -3.0000000000000004e-07 | 2.2e-07 | 1.8999999999999998e-06 |
| 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| COGS Ratio us-gaap:ProductOrService chdn:ChurchillDowns | NA | NA | 35.2 | 60.8 | 23.3 | NA | 39.6 | 31.4 | 182.2 | 21.0 | 28.1 | 10.8 | 154.9 | 2.0 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| COGS Ratio us-gaap:ProductOrService chdn:Gaming | █▆▅▆▁▆▇██▇▅▄▄▄ | 186.0 | 152.0 | 121.7 | 134.8 | 37.3 | 145.9 | 167.7 | 178.3 | 177.6 | 168.8 | 119.5 | 110.4 | 108.1 | 111.5 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| COGS Ratio us-gaap:ProductOrService chdn:LiveAndHistoricalRacing | █▁ | 175.9 | 63.2 | NA | NA | 23.3 | 28.1 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| COGS Ratio us-gaap:ProductOrService chdn:OnlineWagering | NA | NA | 93.9 | 125.9 | 121.2 | NA | 61.6 | 70.2 | 95.6 | 63.1 | 61.5 | 71.8 | 93.7 | 63.2 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| COGS Ratio us-gaap:ProductOrService chdn:TwinSpires | █▁ | 135.6 | 99.7 | NA | NA | 121.3 | 69.1 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| COGS Ratio us-gaap:ProductOrService us-gaap:ProductAndServiceOther | ▅▃█▅▁▃▃▇▆▄▃█▆▄ | 17.6 | 9.4 | 27.4 | 16.3 | 3.3 | 9.8 | 11.7 | 26.4 | 22.0 | 12.5 | 9.9 | 28.3 | 22.7 | 12.6 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| Net profit Margin us-gaap:EquityMethodInvestmentNonconsolidatedInvestee us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees | █▁ | 197.9 | 138.7 | NA | NA | 6.8 | 137.8 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TTM Greenblatt ROC _ _ | ▇▃▂▄▂▁▂▃█▃▂▂▇▂▁▃▇▂▃▃▆▂▂▂▆▁▁▂▅▂▁▂▅▂▂▂▅▂▂▂▄▁ | 135.4 | 46.7 | 22.7 | 49.5 | -0.4 | -11.6 | 3.5 | 27.8 | 156.4 | 28.0 | 12.0 | 20.5 | 136.6 | 19.7 | -12.8 | 33.0 | 129.5 | 17.5 | 32.4 | 26.8 | 117.4 | 6.3 | 12.369 | 9.482 | 105.889 | -4.128 | -13.703 | 8.373 | 94.157 | 1.566 | -5.168 | 10.173 | 82.102 | 2.993 | 3.036 | 7.813 | 82.183 | 3.72 | 6.301 | 10.087 | 67.475 | -2.853 | NA | NA | NA |
| 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:AllocatedShareBasedCompensationExpense | █▁ | 7.1 | 5.5 | NA | 6.9 | 6.1 | 4.3 | NA | 5.5 | 7.4 | 4.7 | NA | 3.9 | 6.4 | 2.8 | NA | NA | NA | NA | NA | NA | NA | NA | NA | 4.485 | 3.372 | 2.723 | 1.365 | 2.213 | 3.113 | 5.241 | 5.915 | 5.99 | 6.214 | 3.363 | 3.126 | 2.968 | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:CostOfGoodsAndServicesSold us-gaap:ProductOrService chdn:ChurchillDowns | NA | NA | 35.9 | 48.3 | 31.1 | 26.6 | 36.0 | 30.8 | 73.6 | 23.4 | 28.9 | 19.5 | 58.0 | 9.9 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:CostOfGoodsAndServicesSold us-gaap:ProductOrService chdn:Gaming | ▇▆▅▅▁▇███▇▅▄▃▄ | 121.0 | 106.3 | 93.29999999999997 | 96.7 | 45.6 | 124.8 | 132.6 | 137.3 | 133.2 | 125.0 | 92.1 | 81.2 | 78.1 | 79.6 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:CostOfGoodsAndServicesSold us-gaap:ProductOrService chdn:LiveAndHistoricalRacing | █▁ | 100.3 | 54.7 | NA | NA | 33.1 | 33.1 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:CostOfGoodsAndServicesSold us-gaap:ProductOrService chdn:OnlineWagering | NA | NA | 65.1 | 83.5 | 74.6 | 50.1 | 46.5 | 52.2 | 62.0 | 45.1 | 43.5 | 49.1 | 59.5 | 44.0 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:CostOfGoodsAndServicesSold us-gaap:ProductOrService chdn:TwinSpires | █▁ | 96.8 | 73.0 | NA | NA | 74.7 | 50.8 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:CostOfGoodsAndServicesSold us-gaap:ProductOrService us-gaap:ProductAndServiceOther | ▃▂█▄▁▄▇▅▄▂▂▅▅▃ | 17.0 | 13.3 | 31.7 | 20.5 | 11.6 | 21.1 | 29.1 | 22.9 | 21.5 | 15.5 | 13.9 | 23.7 | 22.0 | 16.3 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:IncomeLossFromContinuingOperations | █▄▃▅▁▁▂▃█▃▃▅█▃▄▃▆▂▄▃▆▂▃▂▅▂▂▂▅▂▂▃▅▂▂▃▅▂▂▃▄▂▂▂▄ | 108.3 | 36.1 | 16.4 | 43.1 | -23.6 | -22.6 | 4.2 | 15.2 | 108.3 | 11.9 | 7.3 | 58.0 | 103.2 | 14.1 | 34.4 | 12.9 | 72.9 | 2.2 | 26.8 | 8.7 | 69.8 | 2.8 | 7.508 | 4.203 | 55.044 | -1.558 | -13.807 | 3.531 | 57.333 | -0.7 | -5.482 | 9.158 | 50.298 | 1.059 | 2.374 | 5.973 | 48.576 | 1.354 | 4.271 | 19.72 | 39.99 | -3.186 | -4.268 | 3.7 | 28.269 |
| us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest | █▅▄▅▂▂▃▄█▄▃▆█▄▁▄▇▃▄▄▇▃▃▃▆▃▂▃▆▃▃▃▆▃▃▃▆▃▃▄▅▃▃▃▅ | 149.9 | 52.3 | 16.7 | 57.0 | -31.5 | -34.2 | 7.9 | 23.2 | 146.9 | 18.4 | 6.5 | 74.7 | 136.0 | 16.7 | -63.4 | 28.3 | 125.8 | 11.8 | 37.2 | 20.4 | 111.5 | -1.0 | 8.235 | 4.953 | 101.718 | -2.817 | -18.821 | 4.377 | 92.1 | -1.138 | -9.514 | 12.323 | 81.327 | 1.37 | 1.323 | 7.069 | 80.709 | 2.328 | 4.506 | 28.094 | 67.688 | -5.204 | -5.961 | 3.062 | 46.991 |
| us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest | █▄▃▅▁▁▂▃█▃▃▅█▃▄▃▆▂ | 108.3 | 36.1 | 16.4 | 43.2 | -23.6 | -22.5 | 4.5 | 15.2 | 108.3 | 11.9 | 7.3 | 58.0 | 103.2 | 14.1 | 34.4 | 13.1 | 72.7 | 2.2 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:IncomeTaxExpenseBenefit | █▆▅▆▅▅▆▆█▆▅▆▇▆▁▆█▆▆▆█▅▆▆█▅▅▆▇▅▅▆▇▅▅▆▇▆▅▆▇▅▅▅▆ | 41.6 | 16.2 | 0.3 | 13.9 | -7.9 | -11.6 | 3.7 | 8.0 | 38.6 | 6.5 | -0.8 | 16.7 | 32.8 | 2.6 | -83.5 | 11.6 | 47.5 | 4.5 | 10.4 | 11.7 | 41.7 | -3.8 | 0.727 | 0.75 | 46.674 | -1.259 | -5.014 | 0.846 | 34.767 | -0.438 | -4.032 | 3.165 | 31.029 | 0.311 | -1.051 | 1.096 | 32.133 | 0.974 | 0.235 | 8.374 | 27.698 | -2.018 | -1.693 | -0.638 | 18.722 |
| us-gaap:IncomeTaxesPaid | ▃▁▁▁▁▁▂▄▁▁▁▅▅▁▆█▃▁▃▄▁▁▃▆▁▁▁▄▁▁▃▅▁▁▁▅▁▁▃▃ | 10.3 | 0.1 | 0.2 | 0.7 | 0.2 | 0.5 | 7.4 | 14.8 | 0.8 | 0.5 | 0.6 | 24.3 | 23.5 | 0.2 | 27.9 | 39.0 | 8.7 | 0.3 | 10.8 | 19.4 | 0.0 | 2.2 | 11.97 | 29.003 | 0.397 | 0.13 | 0.026 | 16.844 | 0.064 | 0.048 | 10.376 | 20.312 | 0.61 | 0.026 | 2.621 | 21.248 | 0.296 | 0.297 | 10.261 | 13.242 | NA | NA | NA | NA | NA |
| us-gaap:InterestExpense | █▇█▇▇▇▇▇▇▅▄▄▄▄▅▅▅▅▄▄▄▄▃▃▃▃▃▂▂▂▁▁▁▁▁▁▁▁▁▁▂▂▁▁▁ | 22.0 | 19.4 | 20.7 | 19.7 | 20.3 | 19.3 | 18.9 | 18.9 | 19.4 | 13.7 | 10.9 | 9.9 | 9.7 | 9.6 | 13.3 | 12.6 | 11.6 | 11.8 | 10.9 | 11.1 | 11.1 | 10.6 | 7.259 | 6.74 | 7.112 | 7.484 | 5.735 | 5.173 | 4.961 | 4.973 | 2.092 | 1.407 | 1.256 | 1.476 | 1.453 | 0.873 | 0.982 | 1.223 | 1.427 | 1.576 | 3.461 | 2.46 | 1.876 | 1.625 | 1.42 |
| us-gaap:InterestIncomeExpenseNet | ▁█ | -22.0 | -19.4 | NA | -19.7 | -20.3 | -19.3 | NA | -18.9 | -19.4 | -13.7 | NA | -9.9 | -9.7 | -9.6 | NA | -12.6 | -11.6 | -11.8 | -10.9 | -11.1 | -11.1 | -10.6 | -7.449 | -6.732 | -7.106 | -7.266 | -5.73 | -5.167 | -4.956 | -4.969 | -2.085 | -1.401 | -1.167 | -1.466 | -1.447 | -0.842 | -0.947 | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:InterestPaidNet | ▇▅█▆█▆▇▆▁▆▁▆▁▁ | 20.5 | 15.4 | 22.3 | 17.6 | 23.1 | 16.6 | 21.4 | 16.7 | 4.8 | 18.8 | 5.0 | 17.6 | 3.9 | 4.6 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 0.764 | 0.816 | 1.156 | 1.571 | 1.978 | 1.04 | 1.314 | NA |
| us-gaap:LitigationSettlementExpense dei:LegalEntity,us-gaap:LitigationCase,us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations,us-gaap:LitigationStatus chdn:ChurchillDownsIncorporated,chdn:CherylKaterVChurchillDownsIncorporated,chdn:BigFishGames,us-gaap:PendingLitigation | NA | NA | 0.0 | 0.0 | 124.0 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:NetIncomeLoss | ▆▅▄▅▁▃▄▄▆▄▄▅▆█▅▄▆▄▄▄▅▄▄▄▅▄▃▄▅▄▄▄▅▄▄▄▅▄▄▄▅▄▄▄▄ | 108.3 | 36.1 | 17.1 | 43.2 | -118.8 | -23.4 | 4.0 | 14.8 | 107.1 | 11.6 | 11.4 | 56.3 | 103.1 | 182.0 | 38.2 | 16.7 | 78.3 | 7.3 | 26.8 | 8.7 | 69.8 | 2.8 | 7.508 | 4.203 | 55.044 | -1.558 | -13.807 | 3.531 | 57.333 | -0.7 | -5.705 | 9.249 | 50.298 | 1.058 | 2.374 | 5.973 | 48.576 | 1.353 | 7.613 | 19.78 | 40.147 | -3.185 | -1.895 | -0.689 | 27.605 |
| us-gaap:NetIncomeLossAttributableToNoncontrollingInterest | NA | NA | 0.0 | -0.1 | 0.0 | -0.1 | NA | NA | 0.0 | 0.0 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic | ▆▅▄▅▁▃▄▄▆▄▄▅▆█▅▄▆▄ | 108.3 | 36.1 | 17.1 | 43.2 | -118.8 | -23.4 | 4.0 | 14.8 | 107.1 | 11.6 | 11.4 | 56.3 | 103.1 | 182.0 | 38.2 | 16.7 | 78.3 | 7.2 | NA | NA | NA | NA | NA | NA | NA | -1.558 | -13.451 | 3.494 | 56.659 | -0.7 | -5.294 | 9.054 | 49.128 | 1.034 | 2.584 | 5.895 | 47.853 | 1.329 | 7.362 | 19.78 | 39.237 | NA | NA | NA | NA |
| us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted | ▆▅▄▅▁▃▄▄▆▄▄▅▆█▅▄▆▄▄▄▅▄▄▄▅▄▃▄▅▄▄▄▅▄▄▄▅ | 108.3 | 36.1 | 17.1 | 43.2 | -118.8 | -23.4 | 4.0 | 14.8 | 107.1 | 11.6 | 11.4 | 56.3 | 103.1 | 182.0 | 38.2 | 16.7 | 78.3 | 7.3 | 26.8 | 8.7 | 69.8 | 2.8 | 7.508 | 4.203 | 55.044 | -1.6 | -13.807 | 3.531 | 57.333 | -0.7 | -5.705 | 9.249 | 50.298 | 1.034 | 2.374 | 5.973 | 48.576 | NA | 7.613 | 19.78 | 40.147 | NA | NA | NA | NA |
| us-gaap:NonoperatingIncomeExpense | ▅▄▃▄▁▂▄▃▃▃▃█▄▃▁▃▃▃▃▃▃▃▃▃▃▄▃▃▃▃▃▄▃▃▃▃▃▃▃▅▄▃▃▄▃ | 14.5 | 5.6 | -6.0 | 7.5 | -31.1 | -22.6 | 4.4 | -4.6 | -9.5 | -9.6 | -5.5 | 54.2 | -0.6 | -3.0 | -29.1 | -4.7 | -3.7 | -5.7 | -6.5 | -6.4 | -5.9 | -7.3 | -4.134 | -4.529 | -4.171 | 1.311 | -5.118 | -3.996 | -2.057 | -2.704 | -4.346 | 2.15 | -0.775 | -1.623 | -1.713 | -0.744 | -1.474 | -1.392 | -1.795 | 18.007 | 0.213 | -2.351 | -1.691 | -0.233 | -1.334 |
| us-gaap:OperatingExpenses | █▇▆▇▅▆▇▇▇▆▆▆▆▅▁▇▇▆▆▇▇▇▆▆▇ | 379.7 | 277.6 | 255.5 | 288.3 | 185.5 | 264.5 | 277.1 | 278.5 | 321.0 | 237.4 | 207.0 | 200.8 | 242.8 | 169.6 | -129.3 | 281.8 | 322.4 | 262.0 | 234.6 | 276.6 | 321.1 | 282.1 | 260.0 | 270.4 | 303.3 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:OperatingIncomeLoss | ▇▃▂▄▂▁▂▃█▃▂▂▇▂▁▃▇▂▃▃▆▂▂▂▆▁▁▂▅▂▁▂▅▂▂▂▅▂▂▂▄▁▁▂▄ | 135.4 | 46.7 | 22.7 | 49.5 | -0.4 | -11.6 | 3.5 | 27.8 | 156.4 | 28.0 | 12.0 | 20.5 | 136.6 | 19.7 | -12.8 | 33.0 | 129.5 | 17.5 | 32.4 | 26.8 | 117.4 | 6.3 | 12.369 | 9.482 | 105.889 | -4.128 | -13.703 | 8.373 | 94.157 | 1.566 | -5.168 | 10.173 | 82.102 | 2.993 | 3.036 | 7.813 | 82.183 | 3.72 | 6.301 | 10.087 | 67.475 | -2.853 | -4.27 | 3.295 | 48.325 |
| us-gaap:ProfitLoss | █▆▅▆▁▄▅▅█▅ | 108.3 | 36.1 | 17.1 | 43.1 | -118.8 | -23.5 | 3.7 | 14.8 | 107.1 | 11.6 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:Revenues | █▇▆▇▆▆▆▇█▆▆▆▅▅▆▅▅▅▆▅▅▅▆▅▅▅▆▅▅▅▅▅▅▅▅▅▆▆▁▆▆▅▆▆▆ | 515.1 | 324.3 | 278.2 | 337.8 | 185.1 | 252.9 | 280.6 | 306.3 | 477.4 | 265.4 | 219.0 | 221.3 | 0.0 | 0.0 | 178.9 | 0.0 | 0.0 | 0.0 | 278.3 | 0.0 | 0.0 | 0.0 | 272.387 | 0.0 | 0.0 | 0.0 | 168.122 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 270.816 | 138.196 | -547.589 | 166.349 | 249.686 | 131.554 | 137.241 | 147.546 | 215.395 |
| us-gaap:SellingGeneralAndAdministrativeExpense | ▇▆▆█▅▅▇▇▆▅▆▄▅▄▁▅▅▅▅▆▅▅▅▅▄▄▅▄▄▄▅▄▄▄▄▄▄▃▃▃▄▃▄▃▃ | 33.4 | 30.2 | 29.5 | 38.8 | 22.4 | 24.1 | 32.6 | 34.4 | 30.1 | 24.9 | 27.3 | 21.7 | 23.1 | 18.4 | 5.5 | 26.8 | 26.7 | 24.1 | 24.9 | 27.6 | 24.6 | 23.1 | 22.537 | 24.643 | 22.035 | 21.572 | 24.51 | 20.473 | 18.666 | 21.465 | 22.604 | 21.188 | 22.096 | 17.558 | 19.323 | 18.237 | 20.07 | 16.199 | 14.086 | 16.138 | 18.301 | 16.004 | 18.497 | 15.281 | 15.617 |
| 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
|---|
| 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:Assets | ▇▇▆███▆▆▆▆▃▃▃▃▅▅▅▅▅▅▅▅▅▅▅▅▅▂▂▂▂▂▂▁▂▁▁▁▁▁▁ | 2970.6 | 2787.1 | 2686.4 | 3263.0 | 3216.0 | 3203.8 | 2551.0 | 2562.5 | 2588.5 | 2478.5 | 1725.2 | 1711.7 | 1696.6 | 1601.0 | 2359.4 | 2327.4 | 2282.0 | 2256.1 | 2254.4 | 2224.7 | 2248.1 | 2238.3 | 2277.444 | 2260.315 | 2298.99 | 2302.37 | 2360.274 | 1332.264 | 1363.139 | 1351.083 | 1352.261 | 1287.813 | 1129.114 | 1097.14 | 1114.337 | 939.19 | 959.415 | 937.188 | 948.022 | 956.87 | 998.503 | NA | 1017.719 | NA | NA |
| us-gaap:Liabilities | ▇▇▆███▆▆▆▆▄▃▄▄▅▅▅▄▄▄▄▅▅▄▄▅▅▂▂▂▂▂▁▁▁▁▁▁▁▁▁ | 2653.2 | 2584.9 | 2319.3 | 2890.8 | 2893.3 | 2768.2 | 2040.0 | 2012.1 | 2035.2 | 2021.6 | 1251.9 | 1197.0 | 1243.4 | 1257.4 | 1719.1 | 1701.1 | 1680.7 | 1567.2 | 1569.4 | 1529.3 | 1568.3 | 1618.9 | 1660.247 | 1494.146 | 1542.553 | 1603.627 | 1660.273 | 617.265 | 654.054 | 646.457 | 647.472 | 563.585 | 420.194 | 443.0 | 470.042 | 284.835 | 313.814 | 344.407 | 363.992 | 371.081 | 434.207 | NA | 511.505 | NA | NA |
| us-gaap:LiabilitiesAndStockholdersEquity | ▇▇▆███▆▆▆▆▃▃▃▃▅▅▅▅▅▅▅▅▅▅▅▅▅▂▂▂▂▂▂▁▂▁▁▁▁▁▁ | 2970.6 | 2787.1 | 2686.4 | 3263.0 | 3216.0 | 3203.8 | 2551.0 | 2562.5 | 2588.5 | 2478.5 | 1725.2 | 1711.7 | 1696.6 | 1601.0 | 2359.4 | 2327.4 | 2282.0 | 2256.1 | 2254.4 | 2224.7 | 2248.1 | 2238.3 | 2277.444 | 2260.315 | 2298.99 | 2302.37 | 2360.274 | 1332.264 | 1363.139 | 1351.083 | 1352.261 | 1287.813 | 1129.114 | 1097.14 | 1114.337 | 939.19 | 959.415 | 937.188 | 948.022 | 956.87 | 998.503 | NA | 1017.719 | NA | NA |
| us-gaap:StockholdersEquity | NA | NA | 367.1 | 372.2 | 320.1 | 433.0 | 508.3 | 550.4 | 553.3 | 456.9 | 473.3 | 514.7 | 453.2 | 343.6 | 640.3 | 626.3 | 601.3 | 688.9 | 685.0 | 695.4 | 679.8 | 619.4 | 617.197 | 766.169 | 756.437 | 698.743 | 700.001 | 714.999 | 709.085 | 704.626 | 704.789 | 724.228 | 708.92 | 654.14 | 644.295 | 654.355 | 645.601 | 592.781 | 584.03 | 585.789 | 564.296 | NA | 506.214 | NA | NA |
| 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:AssetsCurrent | ▅▃▂███▂▃▃▂▂▂▃▃▂▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁▁▁▁▁▁▁▂ | 532.6 | 346.8 | 235.1 | 806.6 | 817.7 | 843.0 | 221.2 | 301.9 | 348.5 | 259.4 | 241.5 | 230.3 | 354.1 | 294.8 | 256.1 | 234.8 | 208.8 | 213.3 | 246.0 | 201.2 | 209.6 | 198.0 | 222.829 | 209.051 | 215.066 | 202.673 | 241.727 | 126.345 | 153.879 | 149.002 | 160.715 | 147.563 | 156.255 | 133.374 | 147.064 | 133.21 | 151.566 | 124.045 | 144.462 | 145.637 | 177.683 | NA | 169.995 | NA | NA |
| us-gaap:CashAndCashEquivalentsAtCarryingValue | ▄▂▂▇▇█▂▃▃▂▂▂▃▃▁▁▁▁▁▁▁▁▂▁▁▁▂▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁ | 342.2 | 147.7 | 67.4 | 622.0 | 649.2 | 700.9 | 96.2 | 189.8 | 202.7 | 119.7 | 133.3 | 131.3 | 254.6 | 202.7 | 51.7 | 57.8 | 41.8 | 54.9 | 48.7 | 56.9 | 55.1 | 51.1 | 74.528 | 51.112 | 59.244 | 49.525 | 67.936 | 42.041 | 46.67 | 47.164 | 44.708 | 43.751 | 38.917 | 39.288 | 37.177 | 29.999 | 31.787 | 28.882 | 27.325 | 26.883 | 31.031 | 27.348 | 26.901 | 14.533 | 24.251 |
| us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents | ▄▂▁▇██▂▃▃▂▂▂▃▃▁ | 411.4 | 195.7 | 121.0 | 679.6 | 699.0 | 744.5 | 142.5 | 233.8 | 245.5 | 157.4 | 173.3 | 170.1 | 294.7 | 234.2 | 85.5 | NA | NA | NA | 83.0 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:AccountsReceivableNetCurrent | ▄▄▃▅▄▃▃▂▇▄▂▂▃▂▄▇▇▆█▄▆▄▆▆▆▅▇▂▄▂▄▃▄▁▄▃▃▁▄▂▃ | 50.4 | 45.3 | 36.5 | 53.0 | 47.5 | 36.5 | 37.3 | 35.4 | 72.8 | 47.5 | 28.8 | 33.8 | 37.3 | 34.6 | 49.6 | 74.0 | 70.6 | 62.3 | 81.4 | 50.8 | 61.5 | 52.2 | 67.715 | 61.659 | 66.885 | 60.361 | 75.89 | 35.41 | 45.913 | 35.231 | 46.572 | 40.278 | 46.645 | 26.63 | 47.152 | 38.21 | 44.111 | 24.118 | 49.773 | 33.083 | 41.196 | NA | 33.307 | NA | NA |
| us-gaap:OtherAssetsCurrent | ▄▅▄▄▄▅▃▄▄▅▃▃▃▃▂█▇█▇▇▇▇▅▅▄▅▃▂▂▂▁▂▂▃▁▁▂▂▁▂▂ | 31.7 | 36.4 | 28.2 | 33.3 | 34.4 | 36.8 | 26.9 | 31.3 | 30.2 | 37.8 | 22.4 | 26.4 | 22.1 | 26.0 | 18.9 | 59.3 | 54.2 | 57.7 | 50.8 | 51.7 | 51.5 | 53.4 | 39.524 | 38.807 | 33.243 | 35.131 | 24.665 | 16.393 | 18.362 | 20.764 | 12.036 | 14.497 | 17.368 | 22.127 | 13.352 | 11.959 | 14.031 | 17.551 | 10.399 | 18.782 | 20.21 | NA | 20.086 | NA | NA |
| 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:PropertyPlantAndEquipmentGross | NA | NA | 1781.3 | NA | NA | NA | 1547.9 | NA | NA | NA | 1317.2 | NA | NA | NA | 1122.1 | NA | NA | NA | 1051.5 | NA | NA | NA | 1002.972 | NA | NA | NA | 1006.367 | NA | NA | NA | 946.273 | NA | NA | NA | 856.035 | NA | NA | NA | 747.76 | NA | NA | NA | NA | NA | NA | |
| us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType chdn:GrandstandandBuildings | NA | NA | 785.5 | NA | NA | NA | 625.2 | NA | NA | NA | 532.8 | NA | NA | NA | 439.8 | NA | NA | NA | 414.3 | NA | NA | NA | 412.4 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType chdn:TracksAndOtherImprovements | NA | NA | 240.7 | NA | NA | NA | 222.3 | NA | NA | NA | 207.3 | NA | NA | NA | 177.9 | NA | NA | NA | 157.3 | NA | NA | NA | 142.774 | NA | NA | NA | 142.975 | NA | NA | NA | 121.085 | NA | NA | NA | 92.197 | NA | NA | NA | 80.785 | NA | NA | NA | NA | NA | NA | |
| us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType us-gaap:ConstructionInProgress | NA | NA | 23.3 | NA | NA | NA | 52.3 | NA | NA | NA | 7.0 | NA | NA | NA | 23.5 | NA | NA | NA | 27.4 | NA | NA | NA | 22.78 | NA | NA | NA | 15.427 | NA | NA | NA | 15.214 | NA | NA | NA | 7.793 | NA | NA | NA | 4.548 | NA | NA | NA | NA | NA | NA | |
| us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType us-gaap:Equipment | NA | NA | 477.9 | NA | NA | NA | 406.5 | NA | NA | NA | 356.3 | NA | NA | NA | 286.7 | NA | NA | NA | 275.5 | NA | NA | NA | 252.11 | NA | NA | NA | 237.867 | NA | NA | NA | 208.966 | NA | NA | NA | 180.452 | NA | NA | NA | 155.194 | NA | NA | NA | NA | NA | NA | |
| us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType us-gaap:FurnitureAndFixtures | NA | NA | 89.7 | NA | NA | NA | 79.2 | NA | NA | NA | 73.3 | NA | NA | NA | 60.3 | NA | NA | NA | 57.4 | NA | NA | NA | 52.154 | NA | NA | NA | 51.815 | NA | NA | NA | 47.718 | NA | NA | NA | 45.81 | NA | NA | NA | 38.28 | NA | NA | NA | NA | NA | NA | |
| us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType us-gaap:Land | NA | NA | 164.2 | NA | NA | NA | 162.4 | NA | NA | NA | 140.5 | NA | NA | NA | 131.7 | NA | NA | NA | 117.5 | NA | NA | NA | 118.694 | NA | NA | NA | 118.658 | NA | NA | NA | 118.165 | NA | NA | NA | 115.887 | NA | NA | NA | 104.13 | NA | NA | NA | NA | NA | NA | |
| us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment | NA | NA | 721.5 | NA | NA | NA | 635.4 | NA | NA | NA | 559.7 | NA | NA | NA | 514.1 | NA | NA | NA | 477.1 | NA | NA | NA | 429.8 | NA | NA | NA | 411.052 | NA | NA | NA | 360.775 | NA | NA | NA | 313.153 | NA | NA | NA | 270.404 | NA | NA | NA | NA | NA | NA | |
| us-gaap:PropertyPlantAndEquipmentNet | █████▇▆▆▆▆▄▄▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁▁▁▁ | 1057.6 | 1068.7 | 1059.8 | 1081.8 | 1043.2 | 990.8 | 912.5 | 895.2 | 880.0 | 866.5 | 757.5 | 753.4 | 668.5 | 634.9 | 608.0 | 619.4 | 602.8 | 590.7 | 574.4 | 573.3 | 577.9 | 573.2 | 573.172 | 571.457 | 589.552 | 590.17 | 595.315 | 591.678 | 595.926 | 590.586 | 585.498 | 576.142 | 537.333 | 539.238 | 542.882 | 469.52 | 471.954 | 475.48 | 477.356 | 482.005 | 486.973 | NA | 507.476 | NA | NA |
| us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures | ██████████▁▁▂▂▂▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁▁ | 644.6 | 633.7 | 630.6 | 634.0 | 615.4 | 630.0 | 634.5 | 625.0 | 621.8 | 625.7 | 108.1 | 107.9 | 176.8 | 173.4 | 171.3 | 173.9 | 168.0 | 164.7 | 139.1 | 131.4 | 130.4 | 129.8 | 129.746 | 106.302 | 107.465 | 108.606 | 109.548 | 99.198 | 97.488 | 94.692 | 86.151 | NA | NA | NA | 19.24 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:Goodwill | ▃▃▃▃▃▃▃▃▃▃▂▂▂▂▂████████████▂▂▂▂▂▁▁▁▁▁▁▁▁▁ | 366.8 | 366.8 | 366.8 | 366.8 | 366.8 | 367.1 | 367.1 | 363.8 | 363.8 | 363.8 | 338.0 | 337.8 | 317.6 | 317.6 | 317.6 | 848.3 | 847.2 | 832.2 | 832.2 | 841.7 | 841.7 | 841.7 | 841.724 | 841.36 | 840.947 | 840.947 | 839.52 | 300.616 | 300.616 | 300.616 | 300.616 | 298.225 | 250.414 | 250.414 | 250.414 | 217.741 | 217.741 | 216.883 | 213.712 | 213.712 | 213.752 | NA | 214.528 | NA | NA |
| us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill | ▅▅▅▅▅▅▅▅▅▅▄▄▂▂▃▅▅▅▆▅▅▅▇▅▅▅█▂▂▂▃▂▁▁▂▁▁ | 336.0 | 336.0 | 350.6 | 336.0 | 336.0 | 336.0 | 369.8 | 338.2 | 338.2 | 328.2 | 264.0 | 245.5 | 150.2 | 150.2 | 169.4 | 358.3 | 358.3 | 358.3 | 445.7 | 358.3 | 358.3 | 358.3 | 496.153 | 358.343 | 358.343 | 358.343 | 549.972 | 158.343 | 158.343 | 158.343 | 198.149 | 163.301 | 97.511 | 97.511 | 143.141 | 64.71 | 64.71 | NA | 59.91 | NA | NA | NA | NA | NA | NA |
| us-gaap:IntangibleAssetsNetExcludingGoodwill | ▅▅▅▅▅▅▅▅▅▅▄▄▂▂▂▆▆▆▆▇▇▇▇▇███▂▂▂▂▃▂▂▂▁▁▁▁▁▁ | 348.2 | 349.4 | 350.6 | 351.8 | 350.8 | 351.1 | 369.8 | 355.8 | 354.7 | 345.0 | 264.0 | 264.8 | 166.5 | 167.8 | 169.4 | 425.4 | 434.2 | 435.4 | 445.7 | 458.4 | 471.7 | 482.7 | 496.153 | 509.971 | 521.607 | 535.732 | 549.972 | 191.915 | 192.493 | 195.321 | 198.149 | 205.864 | 139.372 | 140.131 | 143.141 | 102.907 | 103.237 | 106.811 | 103.827 | 106.729 | 109.632 | NA | 113.436 | NA | NA |
| us-gaap:FiniteLivedIntangibleAssetsNet | ▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▃▃▄▄▄▅▅▆▆▇▇█▂▂▂▂▂▂▂▂▂▂ | 12.2 | 13.4 | 14.6 | 15.8 | 14.8 | 15.1 | 16.3 | 17.6 | 16.5 | 16.8 | 18.0 | 19.3 | 16.3 | 17.6 | 19.2 | 67.1 | 75.9 | 77.1 | 87.4 | 100.1 | 113.4 | 124.4 | 137.81 | 151.628 | 163.264 | 177.389 | 191.629 | 33.572 | 34.15 | 36.978 | 39.806 | 42.563 | 41.861 | 42.62 | 45.63 | 38.197 | 38.527 | NA | 43.917 | NA | NA | NA | NA | NA | NA |
| us-gaap:OperatingLeaseRightOfUseAsset | NA | NA | 22.3 | NA | NA | NA | 24.8 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:OtherAssetsNoncurrent | ▃▃▃▃▃▃▃▃▃▂▂▂▂▂▂▁▁▁▁▂▂▂▂▃▃▃▃▃▃▃▃█▆▄▄▂▂▂▁▁▁ | 20.8 | 21.7 | 21.2 | 22.0 | 22.1 | 21.8 | 21.1 | 20.8 | 19.7 | 18.1 | 16.1 | 17.5 | 13.1 | 12.5 | 13.6 | 12.3 | 12.3 | 11.7 | 10.7 | 13.5 | 13.0 | 12.9 | 13.82 | 22.174 | 24.353 | 24.242 | 24.192 | 22.512 | 22.737 | 20.866 | 21.132 | 60.019 | 45.74 | 33.983 | 30.836 | 15.812 | 14.917 | 13.969 | 8.665 | 8.787 | 10.463 | NA | 12.284 | NA | NA |
| 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:AccountsPayableCurrent | █▄▄▇▆▄▃▄▇▄▂▃▄▃▂▃▅▂▂▂▄▃▁▂▃▂▂▂▄▂▁▄▄▃▃▃▃▂▂▁▂ | 124.5 | 74.7 | 70.7 | 108.2 | 105.8 | 80.6 | 57.8 | 75.8 | 107.2 | 72.1 | 47.0 | 60.1 | 79.0 | 59.8 | 54.1 | 61.6 | 87.3 | 56.1 | 53.2 | 53.9 | 74.4 | 57.5 | 39.12 | 52.159 | 66.291 | 51.988 | 45.597 | 49.024 | 70.61 | 51.697 | 43.123 | 71.685 | 81.518 | 63.516 | 62.278 | 59.0 | 68.93 | 53.422 | 56.514 | 42.512 | 56.302 | NA | 47.703 | NA | NA |
| us-gaap:ContractWithCustomerLiabilityCurrent | NA | NA | 32.8 | NA | NA | NA | 42.5 | NA | NA | NA | 47.9 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:DividendsPayableCurrent | NA | NA | 24.9 | NA | 0.0 | 0.0 | 23.5 | 0.0 | 0.0 | 0.0 | 22.5 | 0.0 | 0.0 | 0.0 | 23.7 | 0.0 | 0.0 | 0.0 | 21.8 | 0.0 | 0.0 | 0.0 | 19.11 | 0.0 | 0.0 | 0.0 | 17.419 | 0.0 | 0.0 | 0.0 | 15.186 | NA | NA | NA | 0.0 | 0.0 | 0.0 | 0.0 | 10.11 | 0.0 | 0.0 | NA | 8.165 | NA | NA | |
| us-gaap:LiabilitiesCurrent | ▄▃▅▆▆▄▃▃▃▃▂▂▃▃▅▅▅▅▅▄▅▅███▄▄▁▂▂▂▁▂▄▅▁▁▁▁▁▂ | 369.5 | 305.2 | 424.2 | 471.0 | 488.2 | 344.1 | 301.2 | 275.8 | 308.8 | 297.7 | 256.6 | 210.9 | 274.1 | 289.4 | 453.2 | 412.3 | 441.2 | 421.9 | 468.1 | 391.0 | 431.6 | 420.4 | 640.102 | 613.574 | 634.823 | 341.573 | 334.019 | 167.281 | 220.632 | 214.774 | 213.206 | 179.606 | 203.011 | 378.252 | 406.57 | 158.645 | 185.892 | 171.613 | 173.451 | 158.802 | 208.89 | NA | 188.551 | NA | NA |
| us-gaap:LongTermDebtCurrent | ▃▃▁▁▁▁▁▁▁▁▁▁▁▁▁█▇▇▆▆▅▄▇▇▆▅▅ | 7.0 | 7.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 17.7 | 16.5 | 15.3 | 14.2 | 13.0 | 11.8 | 10.6 | 16.25 | 15.0 | 13.75 | 12.5 | 11.25 | NA | NA | NA | 0.0 | 0.0 | 0.0 | 187.318 | 209.728 | NA | NA | NA | 0.0 | NA | NA | NA | NA | NA | NA |
| us-gaap:OperatingLeaseLiabilityCurrent | NA | NA | 4.7 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:LongTermDebt | NA | NA | 1622.3 | NA | NA | NA | 1473.9 | NA | NA | NA | 884.3 | NA | NA | NA | 1129.2 | NA | NA | NA | 921.7 | NA | NA | NA | 781.782 | NA | NA | NA | 759.105 | NA | NA | NA | 369.191 | NA | NA | NA | 209.728 | NA | NA | NA | 127.563 | NA | NA | NA | NA | NA | NA | |
| us-gaap:LongTermDebt us-gaap:CreditFacility,us-gaap:DebtInstrument,us-gaap:FairValueByMeasurementBasis,us-gaap:LongtermDebtType us-gaap:SecuredDebt,chdn:TermLoanBdue2024,us-gaap:CarryingReportedAmountFairValueDisclosure,us-gaap:LineOfCredit | NA | NA | 384.8 | NA | NA | NA | 388.0 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:LongTermDebt us-gaap:CreditFacility,us-gaap:DebtInstrument,us-gaap:LongtermDebtType us-gaap:SecuredDebt,chdn:A2017CreditAgreement,us-gaap:LineOfCredit | NA | NA | 384.8 | NA | NA | NA | 388.0 | NA | NA | NA | 391.3 | NA | NA | NA | 394.9 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:LongTermDebt us-gaap:DebtInstrument,us-gaap:FairValueByMeasurementBasis,us-gaap:LongtermDebtType chdn:Revolver,us-gaap:CarryingReportedAmountFairValueDisclosure,us-gaap:LineOfCredit | NA | NA | 149.7 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:LongTermDebt us-gaap:DebtInstrument,us-gaap:FairValueByMeasurementBasis,us-gaap:LongtermDebtType chdn:SeniorNotesDue2027,us-gaap:CarryingReportedAmountFairValueDisclosure,us-gaap:SeniorNotes | NA | NA | 593.2 | NA | NA | NA | 592.0 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:LongTermDebt us-gaap:DebtInstrument,us-gaap:FairValueByMeasurementBasis,us-gaap:LongtermDebtType chdn:SeniorNotesDue2028,us-gaap:CarryingReportedAmountFairValueDisclosure,us-gaap:SeniorNotes | NA | NA | 494.6 | NA | NA | NA | 493.9 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:LongTermDebt us-gaap:DebtInstrument,us-gaap:LongtermDebtType chdn:Revolver,us-gaap:LineOfCredit | NA | NA | 149.7 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:LongTermDebt us-gaap:DebtInstrument,us-gaap:LongtermDebtType chdn:SeniorNotesDue2027,us-gaap:SeniorNotes | NA | NA | 593.2 | NA | NA | NA | 592.0 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:LongTermDebt us-gaap:DebtInstrument,us-gaap:LongtermDebtType chdn:SeniorNotesDue2028,us-gaap:SeniorNotes | NA | NA | 494.6 | NA | NA | NA | 493.9 | NA | NA | NA | 493.0 | NA | NA | NA | 492.3 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:LongTermDebt us-gaap:EquityMethodInvestmentNonconsolidatedInvestee us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees | █▁▅ | 772.0 | 722.0 | 753.5 | NA | NA | NA | 745.0 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:LongTermDebtNoncurrent | NA | NA | 1618.3 | NA | NA | NA | 1469.9 | 384.8 | 385.6 | 386.5 | 880.3 | 388.2 | 389.0 | 390.1 | 1125.2 | 510.7 | 459.9 | 358.0 | 907.5 | 312.7 | 319.7 | 382.7 | 765.532 | 272.136 | 299.992 | 387.257 | 459.105 | 383.391 | 368.798 | 365.75 | 369.191 | 324.782 | 153.484 | NA | 0.0 | 69.998 | 62.964 | 107.761 | 127.563 | 156.27 | 184.961 | NA | 265.117 | NA | NA | |
| us-gaap:DeferredFinanceCostsNoncurrentNet | NA | NA | 12.2 | NA | NA | NA | 14.1 | NA | NA | NA | 7.0 | NA | NA | NA | 7.7 | NA | NA | NA | 7.8 | NA | NA | NA | 9.3 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:DeferredIncomeTaxLiabilitiesNet | ██▇▆▅▆▆▆▆▆▁ | 250.5 | 248.8 | 213.9 | 205.4 | 188.0 | 210.9 | 212.8 | 209.8 | 199.9 | 194.0 | 78.2 | NA | NA | NA | 40.6 | NA | NA | NA | 63.2 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:OtherLiabilitiesNoncurrent | █▇▆▅▅▅▅▅▅▅▁▁▁▁▁▂▂▁▁▁▁▂▂▂▃▂▂▂▂▂▁▂▂▂▂▂▄▄▃▄▁ | 55.7 | 48.2 | 45.8 | 36.6 | 38.1 | 38.6 | 39.4 | 38.9 | 38.8 | 38.1 | 15.7 | 17.5 | 17.9 | 16.6 | 16.0 | 19.2 | 18.3 | 17.5 | 16.3 | 15.6 | 15.2 | 18.4 | 18.282 | 23.779 | 24.521 | 23.119 | 21.718 | 20.061 | 19.572 | 18.299 | 17.753 | 18.22 | 23.246 | 21.513 | 21.03 | 22.458 | 31.976 | 30.621 | 29.542 | 30.181 | 16.035 | NA | 17.775 | NA | NA |
| us-gaap:OperatingLeaseLiabilityNoncurrent | NA | NA | 19.0 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo | NA | NA | 4.3 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree | NA | NA | 3.8 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour | NA | NA | 3.8 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive | NA | NA | 3.6 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive | NA | NA | 5.5 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:StockholdersEquity | NA | NA | 367.1 | 372.2 | 320.1 | 433.0 | 508.3 | 550.4 | 553.3 | 456.9 | 473.3 | 514.7 | 453.2 | 343.6 | 640.3 | 626.3 | 601.3 | 688.9 | 685.0 | 695.4 | 679.8 | 619.4 | 617.197 | 766.169 | 756.437 | 698.743 | 700.001 | 714.999 | 709.085 | 704.626 | 704.789 | 724.228 | 708.92 | 654.14 | 644.295 | 654.355 | 645.601 | 592.781 | 584.03 | 585.789 | 564.296 | NA | 506.214 | NA | NA | |
| us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest | ▃▁▄▄▃▆▇██▆▆ | 317.4 | 202.2 | 367.1 | 372.2 | 322.7 | 435.6 | 511.0 | 550.4 | 553.3 | 456.9 | 473.3 | NA | NA | NA | 640.3 | NA | NA | NA | 685.0 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:CommonStockValue | ▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▄▄▄▄▄▄▇▇▇▇▇▇█████▇▇▇▇▇▇▇ | 8.8 | 1.7 | 18.2 | 15.5 | 6.1 | 0.0 | 0.0 | 0.0 | 2.9 | 0.0 | 0.0 | 11.5 | 6.0 | 0.0 | 7.3 | 0.0 | 0.0 | 113.2 | 116.5 | 130.7 | 123.8 | 133.4 | 134.026 | 271.116 | 265.645 | 262.967 | 262.28 | 246.001 | 243.618 | 296.492 | 295.955 | 294.037 | 287.978 | 283.496 | 274.709 | 274.622 | 271.841 | 267.597 | 260.199 | 259.336 | 257.623 | NA | 236.503 | NA | NA |
| us-gaap:RetainedEarningsAccumulatedDeficit | ▃▁▃▄▃▅▆▇▇▅▅▆▅▃██▇▇▇▇▇▆▆▆▆▅▅▅▅▄▄▅▅▄▄▄▄▃▃▃▃ | 309.5 | 201.4 | 349.8 | 357.6 | 314.9 | 433.9 | 509.2 | 551.3 | 551.3 | 457.8 | 474.2 | 504.1 | 448.1 | 344.5 | 634.3 | 627.3 | 602.8 | 577.0 | 569.7 | 565.1 | 556.4 | 486.6 | 483.759 | 495.535 | 491.332 | 436.288 | 437.846 | 468.998 | 465.467 | 408.134 | 408.834 | 430.191 | 420.942 | 370.644 | 369.586 | 379.733 | 373.76 | 325.184 | 323.831 | 326.453 | 306.673 | NA | 269.711 | NA | NA |
| us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue | NA | NA | NA | 6.9 | 6.1 | 4.3 | NA | 5.5 | 7.4 | 4.7 | NA | 3.9 | 6.4 | 6.2 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:NetCashProvidedByUsedInOperatingActivities | █▁▂▃▃▃▃▃▆▄▃▁▅▃▃▂▄▄▃▂▄▄▃▃▅▄▂▂▄▃▃▂▃▃▃▂▃▃▃▂▃▃▂▂ | 230.1 | -19.8 | 4.6 | 60.4 | 33.4 | 43.5 | 29.4 | 45.9 | 144.0 | 70.3 | 62.4 | -26.9 | 106.4 | 55.9 | 54.0 | -6.9 | 96.5 | 74.6 | 37.8 | 22.2 | 100.2 | 66.6 | 41.33 | 29.018 | 104.504 | 89.674 | 27.374 | -4.843 | 67.157 | 51.931 | 30.542 | 14.109 | 53.549 | 46.715 | 42.298 | 6.059 | 40.941 | 55.109 | 41.546 | 26.823 | 44.334 | 60.475 | 4.516 | -2.545 | NA |
| us-gaap:NetCashProvidedByUsedInInvestingActivities | ▄▄▄▃▃▄▃▄▄▁▄▄▄█▄▄▄▄▄▄▄▄▄▄▄▄▂▄▄▄▄▃▄▄▃▄▄▄▄▄▄▄▃▄ | -18.2 | -12.3 | -26.6 | -81.0 | -83.5 | -48.3 | -90.6 | -36.7 | -34.8 | -619.1 | -24.8 | -43.5 | -44.3 | 936.7 | -29.0 | -27.3 | -45.9 | -51.4 | -4.5 | -10.6 | -20.6 | -15.0 | -37.131 | -10.382 | -12.888 | -5.084 | -380.885 | -12.211 | -19.335 | -27.877 | -60.93 | -178.418 | -22.721 | -19.803 | -164.074 | -7.92 | -5.146 | -22.848 | -7.784 | -5.333 | -8.861 | -5.083 | -142.869 | -6.656 | NA |
| us-gaap:NetCashProvidedByUsedInFinancingActivities | ▅▆▂▅▅█▅▅▅█▅▅▅▁▅▅▅▅▅▅▅▅▅▅▅▅▇▅▅▅▅▆▅▅▆▅▅▅▅▅▅▅▆▅ | 3.8 | 106.8 | -536.6 | 1.2 | 4.6 | 606.8 | -30.1 | -20.9 | -21.1 | 532.9 | -34.2 | -54.2 | -1.1 | -843.8 | -27.8 | 49.6 | -64.3 | -17.0 | -41.9 | -9.1 | -75.8 | -75.1 | 19.712 | -27.009 | -82.242 | -101.105 | 379.538 | 12.425 | -48.316 | -21.598 | 31.345 | 169.143 | -31.199 | -24.801 | 128.954 | 0.073 | -32.89 | -30.704 | -33.32 | -25.638 | -31.79 | -54.945 | 150.721 | -0.517 | NA |
| us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect | ▆▅▁▄▄█▄▄▅▄▄▄▅▅ | 215.7 | 74.7 | -558.6 | -19.4 | -45.5 | 602.0 | -91.3 | -11.7 | 88.1 | -15.9 | 3.4 | -124.6 | 61.0 | 148.8 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet | ▂▄█▄▁▅▅▄▃▅▄▅▃▅▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄ | -85.6 | -2.2 | 169.0 | -36.5 | -151.7 | 24.3 | 31.7 | -9.2 | -57.1 | 22.0 | -0.1 | 38.6 | -55.9 | 11.4 | -3.3 | -9.4 | 6.0 | 1.2 | -2.5 | -1.9 | 3.9 | -0.8 | 5.696 | -0.485 | -1.488 | -3.648 | 0.8 | -0.247 | -1.58 | -0.511 | -1.478 | -0.411 | -0.276 | -0.234 | 4.486 | 0.739 | -1.685 | -0.782 | -0.051 | -14.718 | -0.674 | -1.106 | 2.711 | -0.203 | NA |
| us-gaap:NetCashProvidedByUsedInOperatingActivities | █▁▂▃▃▃▃▃▆▄▃▁▅▃▃▂▄▄▃▂▄▄▃▃▅▄▂▂▄▃▃▂▃▃▃▂▃▃▃▂▃▃▂▂ | 230.1 | -19.8 | 4.6 | 60.4 | 33.4 | 43.5 | 29.4 | 45.9 | 144.0 | 70.3 | 62.4 | -26.9 | 106.4 | 55.9 | 54.0 | -6.9 | 96.5 | 74.6 | 37.8 | 22.2 | 100.2 | 66.6 | 41.33 | 29.018 | 104.504 | 89.674 | 27.374 | -4.843 | 67.157 | 51.931 | 30.542 | 14.109 | 53.549 | 46.715 | 42.298 | 6.059 | 40.941 | 55.109 | 41.546 | 26.823 | 44.334 | 60.475 | 4.516 | -2.545 | NA |
| us-gaap:NetIncomeLoss | ▆▅▄▅▁▃▄▄▆▄▄▅▆█▅▄▆▄▄▄▅▄▄▄▅▄▃▄▅▄▄▄▅▄▄▄▅▄▄▄▅▄▄▄▄ | 108.3 | 36.1 | 17.1 | 43.2 | -118.8 | -23.4 | 4.0 | 14.8 | 107.1 | 11.6 | 11.4 | 56.3 | 103.1 | 182.0 | 38.2 | 16.7 | 78.3 | 7.3 | 26.8 | 8.7 | 69.8 | 2.8 | 7.508 | 4.203 | 55.044 | -1.558 | -13.807 | 3.531 | 57.333 | -0.7 | -5.705 | 9.249 | 50.298 | 1.058 | 2.374 | 5.973 | 48.576 | 1.353 | 7.613 | 19.78 | 40.147 | -3.185 | -1.895 | -0.689 | 27.605 |
| us-gaap:ProfitLoss | █▆▅▆▁▄▅▅█▅ | 108.3 | 36.1 | 17.1 | 43.1 | -118.8 | -23.5 | 3.7 | 14.8 | 107.1 | 11.6 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:ShareBasedCompensation | ▆▅▅▆▅▄▅▅▆▄▄▃▅▅█▅▆▄▄▄▅▄▃▄▃▃▁▂▃▅▅▅▅▃▂▂▄▂▁▁▂▂▂▁ | 7.1 | 5.5 | 6.4 | 6.9 | 6.1 | 4.3 | 6.2 | 5.5 | 7.4 | 4.7 | 4.6 | 3.9 | 6.4 | 6.1 | 9.6 | 5.8 | 6.7 | 4.9 | 4.6 | 4.9 | 5.3 | 4.1 | 3.22 | 4.5 | 3.4 | 2.723 | 1.364 | 2.213 | 3.113 | 5.241 | 5.915 | 5.99 | 6.214 | 3.363 | 1.53 | 1.669 | 4.715 | 1.924 | 1.199 | 1.366 | 1.435 | 1.531 | 2.414 | 0.802 | NA |
| 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:NetCashProvidedByUsedInInvestingActivities | ▄▄▄▃▃▄▃▄▄▁▄▄▄█▄▄▄▄▄▄▄▄▄▄▄▄▂▄▄▄▄▃▄▄▃▄▄▄▄▄▄▄▃▄ | -18.2 | -12.3 | -26.6 | -81.0 | -83.5 | -48.3 | -90.6 | -36.7 | -34.8 | -619.1 | -24.8 | -43.5 | -44.3 | 936.7 | -29.0 | -27.3 | -45.9 | -51.4 | -4.5 | -10.6 | -20.6 | -15.0 | -37.131 | -10.382 | -12.888 | -5.084 | -380.885 | -12.211 | -19.335 | -27.877 | -60.93 | -178.418 | -22.721 | -19.803 | -164.074 | -7.92 | -5.146 | -22.848 | -7.784 | -5.333 | -8.861 | -5.083 | -142.869 | -6.656 | NA |
| 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:NetCashProvidedByUsedInFinancingActivities | ▅▆▂▅▅█▅▅▅█▅▅▅▁▅▅▅▅▅▅▅▅▅▅▅▅▇▅▅▅▅▆▅▅▆▅▅▅▅▅▅▅▆▅ | 3.8 | 106.8 | -536.6 | 1.2 | 4.6 | 606.8 | -30.1 | -20.9 | -21.1 | 532.9 | -34.2 | -54.2 | -1.1 | -843.8 | -27.8 | 49.6 | -64.3 | -17.0 | -41.9 | -9.1 | -75.8 | -75.1 | 19.712 | -27.009 | -82.242 | -101.105 | 379.538 | 12.425 | -48.316 | -21.598 | 31.345 | 169.143 | -31.199 | -24.801 | 128.954 | 0.073 | -32.89 | -30.704 | -33.32 | -25.638 | -31.79 | -54.945 | 150.721 | -0.517 | NA |
| us-gaap:PaymentsOfDividends | ▁█▁▁▁█▁▁▁▇▁▁▁█▁▁▁▇▁▁▁▆▁▁▁▆▁▁▁▅▁▁▁▁▅▁▁▄▁▁▁▃▁▁ | 0.0 | 24.8 | 0.0 | 0.0 | 0.0 | 23.4 | 0.0 | 0.0 | 0.0 | 22.2 | 0.2 | 0.0 | -0.2 | 23.7 | -0.3 | 0.0 | 0.0 | 21.8 | 0.0 | 0.0 | 0.0 | 19.1 | 0.0 | 0.0 | 0.0 | 17.419 | 0.0 | 0.0 | 0.0 | 15.186 | 0.0 | 0.0 | 0.0 | 0.0 | 12.351 | 0.0 | 0.0 | 10.11 | 0.0 | 0.0 | 0.0 | 8.165 | 0.0 | 0.0 | NA |
| us-gaap:PaymentsForRepurchaseOfCommonStock | ▁▄▁▁▁▁▁▁▁▁▁▁▁█▁▁▃▁▁▁▁▁▃▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁ | 0.0 | 193.9 | 0.0 | 0.0 | 0.0 | 28.4 | 28.2 | 21.3 | 11.4 | 34.1 | 32.3 | 0.0 | 0.3 | 514.4 | 9.8 | 0.1 | 172.4 | 8.6 | 19.0 | 2.4 | 16.8 | 0.8 | 140.371 | 1.254 | 1.029 | 4.9 | 5.723 | 1.177 | 0.719 | 7.402 | 4.783 | 1.894 | 3.039 | 1.007 | 2.248 | 0.813 | 1.765 | 0.268 | 0.576 | 0.287 | 0.294 | 0.151 | -0.41 | 0.167 | NA |
| 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
|---|
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 8.8 | 1.7 | 18 | 15 | 6.1 | 0.0 | 0.0 | 0.0 | 2.9 | 0.0 | 0.0 | 11 | 6.0 | 0.0 | 7.3 | 0.0 | 0.0 | 113 | 116 | 130 | 123 | 133 | 134 | 271 | 265 | 262 | 262 | 246 | 243 | 296 | 295 | 294 | 287 | 283 | 274 | 274 | 271 | 267 | 260 | 259 | 257 | 236 |
| Percentage of CommonStockValue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 0.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 0.3 | 0.1 | 0.7 | 0.5 | 0.2 | 0.0 | 0.0 | 0.0 | 0.1 | 0.0 | 0.0 | 0.7 | 0.4 | 0.0 | 0.3 | 0.0 | 0.0 | 5.0 | 5.2 | 5.9 | 5.5 | 6.0 | 5.9 | 12.0 | 11.6 | 11.4 | 11.1 | 18.5 | 17.9 | 21.9 | 21.9 | 22.8 | 25.5 | 25.8 | 24.7 | 29.2 | 28.3 | 28.6 | 27.4 | 27.1 | 25.8 | 23.2 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 | 2010-12-31 | 2009-12-31 | 2008-12-31 |
| Value | 38 | 38 | 39 | 39 | 39 | 39 | 39 | 39 | 40 | 40 | 40 | 40 | 40 | 40 | 15 | 16 | 16 | 17 | 17 | 17 | 17 | 16 | 13 | 13 |
| Percentage of SharesOutstanding | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 39 | 39 | 39 | 40 | 40 | 40 | 13 | 13 | 16 | 15 | 15 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 0.017403 | 17 | 17 | 17 | 17 | 16 |
| Percentage of CommonStockSharesIssued | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 |
| Value | 39 | 39 | 39 | 40 | 40 | 40 | 15 | 16 |
| Percentage of CommonStockSharesOutstanding | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-09-30 | 2010-06-30 |
| Value | 39 | 39 | 40 | 39 | 39 | 40 | 40 | 40 | 13 | 13 | 14 | 15 | 16 | 16 | 16 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 16 | 16 | 16 | 16 | 14 |
| Percentage of WeightedAverageNumberOfDilutedSharesOutstanding | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-09-30 | 2010-06-30 |
| Value | 38 | 39 | 39 | 39 | 39 | 40 | 40 | 40 | 13 | 13 | 14 | 15 | 16 | 16 | 16 | 16 | 16 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 16 | 16 | 16 | 16 | 16 | 16 | 14 |
| Percentage of WeightedAverageNumberOfSharesOutstandingBasic | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 2.8 | 0.93 | 0.43 | 1.09 | -3.0 | -590000.0 | 0.1 | 0.37 | 2.66 | 0.29 | 0.28 | 4.15 | 7.6 | 12.61 | 2.5 | 1.09 | 4.86 | 0.44 | 1.62 | 0.52 | 4.16 | 0.17 | 0.44 | 0.24 | 3.12 | -0.09 | -0.81 | 0.21 | 3.23 | -0.04 | -0.32 | 0.52 | 2.85 | 0.06 | 0.15 | 0.34 | 2.82 | 0.08 | 0.43 | 1.17 | 2.39 | -0.19 | -0.14 | -0.04 | 1.85 |
| Percentage of EarningsPerShareBasic | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 2.76 | 0.91 | 0.43 | 1.08 | -3.0 | -590000.0 | 0.1 | 0.36 | 2.63 | 0.29 | 0.28 | 4.12 | 7.55 | 12.55 | 2.46 | 1.08 | 4.81 | 0.44 | 1.6 | 0.52 | 4.11 | 0.16 | 0.43 | 0.24 | 3.1 | -0.09 | -0.81 | 0.2 | 3.21 | -0.04 | -0.33 | 0.52 | 2.81 | 0.06 | 0.14 | 0.34 | 2.77 | 0.08 | 0.41 | 1.17 | 2.37 | -0.19 | -0.15 | -0.04 | 1.85 |
| Percentage of EarningsPerShareDiluted | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2013-12-31 | 2013-09-30 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 2.8 | 0.93 | 0.41 | 1.09 | -0.59 | -570000.0 | 0.11 | 0.38 | 2.69 | 0.3 | 0.18 | 4.27 | 7.61 | 0.98 | 2.25 | 0.85 | 4.52 | 0.13 | 1.17 | 0.2 | 3.97 | 0.43 | -0.3 | 0.52 | 0.15 | 0.34 | 2.82 | 0.23 | 1.17 | 2.38 | -0.29 | 0.22 | 1.9 |
| Percentage of IncomeLossFromContinuingOperationsPerBasicShare | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2014-12-31 | 2014-09-30 | 2013-12-31 | 2013-09-30 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 2.76 | 0.91 | 0.41 | 1.08 | -0.59 | -570000.0 | 0.11 | 0.37 | 2.66 | 0.3 | 0.18 | 4.24 | 7.57 | 0.97 | 2.22 | 0.84 | 4.47 | 0.13 | 1.16 | 0.2 | 3.93 | 0.42 | -0.76 | 0.2 | -0.31 | 0.51 | 0.14 | 0.34 | 2.77 | 0.21 | 1.16 | 2.36 | -0.3 | 0.22 | 1.9 |
| Percentage of IncomeLossFromContinuingOperationsPerDilutedShare | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 |
| Value | 7.1 | 5.5 | 6.9 | 6.1 | 4.3 | 5.5 | 7.4 | 4.7 | 3.9 | 6.4 | 2.8 | 4.485 | 3.372 | 2.723 | 1.365 | 2.213 | 3.113 | 5.241 | 5.915 | 5.99 | 6.214 | 3.363 | 3.126 | 2.968 |
| Percentage of AllocatedShareBasedCompensationExpense | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 1.4 | 1.7 | 2.0 | 3.3 | 1.7 | 1.8 | 1.6 | 1.8 | 1.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 35 | 48 | 31 | 26 | 36 | 30 | 73 | 23 | 28 | 19 | 58 | 9.9 |
| Percentage of CostOfGoodsAndServicesSold | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 12.9 | 14.3 | 16.8 | 10.5 | 12.8 | 10.1 | 15.4 | 8.8 | 13.2 | 8.8 | 0.0 | 0.0 |
| Percentage of Revenues chdn:ChurchillDowns | 0.0 | 79.4 | 133.5 | 0.0 | 0.0 | 98.1 | 40.4 | 111.4 | 0.0 | 180.6 | 37.4 | 495.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 121 | 106 | 93 | 96 | 45 | 124 | 132 | 137 | 133 | 125 | 92 | 81 | 78 | 79 |
| Percentage of CostOfGoodsAndServicesSold | 0.0 | 0.0 | 259.9 | 200.2 | 146.6 | 469.2 | 368.3 | 445.8 | 181.0 | 534.2 | 318.7 | 416.4 | 134.7 | 804.0 |
| Percentage of Revenues | 23.5 | 32.8 | 33.5 | 28.6 | 24.6 | 49.3 | 47.3 | 44.8 | 27.9 | 47.1 | 42.1 | 36.7 | 0.0 | 0.0 |
| Percentage of Revenues chdn:Gaming | 65.1 | 69.9 | 0.0 | 71.7 | 122.3 | 85.5 | 0.0 | 77.0 | 75.0 | 74.1 | 0.0 | 73.6 | 72.2 | 71.4 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 100 | 54 | 33 | 33 |
| Percentage of CostOfGoodsAndServicesSold | 0.0 | 0.0 | 106.4 | 124.4 |
| Percentage of Revenues | 19.5 | 16.9 | 17.9 | 13.1 |
| Percentage of Revenues chdn:LiveAndHistoricalRacing | 57.0 | 86.6 | 142.1 | 117.8 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 65 | 83 | 74 | 50 | 46 | 52 | 62 | 45 | 43 | 49 | 59 | 44 |
| Percentage of CostOfGoodsAndServicesSold | 181.3 | 172.9 | 239.9 | 188.3 | 129.2 | 169.5 | 84.2 | 192.7 | 150.5 | 251.8 | 102.6 | 444.4 |
| Percentage of Revenues | 23.4 | 24.7 | 40.3 | 19.8 | 16.6 | 17.0 | 13.0 | 17.0 | 19.9 | 22.2 | 0.0 | 0.0 |
| Percentage of Revenues chdn:OnlineWagering | 0.0 | 66.3 | 61.6 | 0.0 | 0.0 | 74.4 | 64.9 | 71.5 | 0.0 | 68.4 | 63.5 | 69.6 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 96 | 73 | 74 | 50 |
| Percentage of CostOfGoodsAndServicesSold | 0.0 | 0.0 | 240.2 | 191.0 |
| Percentage of Revenues | 18.8 | 22.5 | 40.4 | 20.1 |
| Percentage of Revenues chdn:TwinSpires | 71.4 | 73.2 | 61.6 | 73.5 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 17 | 13 | 31 | 20 | 11 | 21 | 29 | 22 | 21 | 15 | 13 | 23 | 22 | 16 |
| Percentage of CostOfGoodsAndServicesSold | 0.0 | 0.0 | 88.3 | 42.4 | 37.3 | 79.3 | 80.8 | 74.4 | 29.2 | 66.2 | 48.1 | 121.5 | 37.9 | 164.6 |
| Percentage of Revenues | 3.3 | 4.1 | 11.4 | 6.1 | 6.3 | 8.3 | 10.4 | 7.5 | 4.5 | 5.8 | 6.3 | 10.7 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:ProductAndServiceOther | 96.6 | 141.5 | 0.0 | 125.8 | 351.5 | 215.3 | 0.0 | 86.7 | 97.7 | 124.0 | 0.0 | 83.7 | 96.9 | 129.4 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 108 | 36 | 16 | 43 | -23.6 | -22.6 | 4.2 | 15 | 108 | 11 | 7.3 | 58 | 103 | 14 | 34 | 12 | 72 | 2.2 | 26 | 8.7 | 69 | 2.8 | 7.508 | 4.203 | 55 | -1.558 | -13.807 | 3.531 | 57 | -0.7 | -5.482 | 9.158 | 50 | 1.059 | 2.374 | 5.973 | 48 | 1.354 | 4.271 | 19 | 39 | -3.186 | -4.268 | 3.7 | 28 |
| Percentage of IncomeLossFromContinuingOperations | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 21.0 | 11.1 | 5.9 | 12.8 | -12.7 | -8.9 | 1.5 | 5.0 | 22.7 | 4.5 | 3.3 | 26.2 | 0.0 | 0.0 | 19.2 | 0.0 | 0.0 | 0.0 | 9.6 | 0.0 | 0.0 | 0.0 | 2.8 | 0.0 | 0.0 | 0.0 | -8.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 17.9 | 1.0 | -0.8 | 11.9 | 16.0 | -2.4 | -3.1 | 2.5 | 13.1 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 149 | 52 | 16 | 57 | -31.5 | -34.2 | 7.9 | 23 | 146 | 18 | 6.5 | 74 | 136 | 16 | -63.4 | 28 | 125 | 11 | 37 | 20 | 111 | -1.0 | 8.235 | 4.953 | 101 | -2.817 | -18.821 | 4.377 | 92 | -1.138 | -9.514 | 12 | 81 | 1.37 | 1.323 | 7.069 | 80 | 2.328 | 4.506 | 28 | 67 | -5.204 | -5.961 | 3.062 | 46 |
| Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 29.1 | 16.1 | 6.0 | 16.9 | -17.0 | -13.5 | 2.8 | 7.6 | 30.8 | 6.9 | 3.0 | 33.8 | 0.0 | 0.0 | -35.4 | 0.0 | 0.0 | 0.0 | 13.4 | 0.0 | 0.0 | 0.0 | 3.0 | 0.0 | 0.0 | 0.0 | -11.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 29.8 | 1.7 | -0.8 | 16.9 | 27.1 | -4.0 | -4.3 | 2.1 | 21.8 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 |
| Value | 108 | 36 | 16 | 43 | -23.6 | -22.5 | 4.5 | 15 | 108 | 11 | 7.3 | 58 | 103 | 14 | 34 | 13 | 72 | 2.2 |
| Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 21.0 | 11.1 | 5.9 | 12.8 | -12.7 | -8.9 | 1.6 | 5.0 | 22.7 | 4.5 | 3.3 | 26.2 | 0.0 | 0.0 | 19.2 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 41 | 16 | 0.3 | 13 | -7.9 | -11.6 | 3.7 | 8.0 | 38 | 6.5 | -0.8 | 16 | 32 | 2.6 | -83.5 | 11 | 47 | 4.5 | 10 | 11 | 41 | -3.8 | 0.727 | 0.75 | 46 | -1.259 | -5.014 | 0.846 | 34 | -0.438 | -4.032 | 3.165 | 31 | 0.311 | -1.051 | 1.096 | 32 | 0.974 | 0.235 | 8.374 | 27 | -2.018 | -1.693 | -0.638 | 18 |
| Percentage of IncomeTaxExpenseBenefit | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 8.1 | 5.0 | 0.1 | 4.1 | -4.3 | -4.6 | 1.3 | 2.6 | 8.1 | 2.4 | -0.4 | 7.5 | 0.0 | 0.0 | -46.7 | 0.0 | 0.0 | 0.0 | 3.7 | 0.0 | 0.0 | 0.0 | 0.3 | 0.0 | 0.0 | 0.0 | -3.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 11.9 | 0.7 | -0.0 | 5.0 | 11.1 | -1.5 | -1.2 | -0.4 | 8.7 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 |
| Value | 10 | 0.1 | 0.2 | 0.7 | 0.2 | 0.5 | 7.4 | 14 | 0.8 | 0.5 | 0.6 | 24 | 23 | 0.2 | 27 | 39 | 8.7 | 0.3 | 10 | 19 | 0.0 | 2.2 | 11 | 29 | 0.397 | 0.13 | 0.026 | 16 | 0.064 | 0.048 | 10 | 20 | 0.61 | 0.026 | 2.621 | 21 | 0.296 | 0.297 | 10 | 13 |
| Percentage of IncomeTaxesPaid | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 2.0 | 0.0 | 0.1 | 0.2 | 0.1 | 0.2 | 2.6 | 4.8 | 0.2 | 0.2 | 0.3 | 11.0 | 0.0 | 0.0 | 15.6 | 0.0 | 0.0 | 0.0 | 3.9 | 0.0 | 0.0 | 0.0 | 4.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 0.2 | -1.9 | 8.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 22 | 19 | 20 | 19 | 20 | 19 | 18 | 18 | 19 | 13 | 10 | 9.9 | 9.7 | 9.6 | 13 | 12 | 11 | 11 | 10 | 11 | 11 | 10 | 7.259 | 6.74 | 7.112 | 7.484 | 5.735 | 5.173 | 4.961 | 4.973 | 2.092 | 1.407 | 1.256 | 1.476 | 1.453 | 0.873 | 0.982 | 1.223 | 1.427 | 1.576 | 3.461 | 2.46 | 1.876 | 1.625 | 1.42 |
| Percentage of InterestExpense | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 4.3 | 6.0 | 7.4 | 5.8 | 11.0 | 7.6 | 6.7 | 6.2 | 4.1 | 5.2 | 5.0 | 4.5 | 0.0 | 0.0 | 7.4 | 0.0 | 0.0 | 0.0 | 3.9 | 0.0 | 0.0 | 0.0 | 2.7 | 0.0 | 0.0 | 0.0 | 3.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.4 | 0.9 | -0.3 | 0.9 | 1.4 | 1.9 | 1.4 | 1.1 | 0.7 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 |
| Value | -22000000.0 | -19400000.0 | -19700000.0 | -20300000.0 | -19300000.0 | -18900000.0 | -19400000.0 | -13700000.0 | -9900000.0 | -9700000.0 | -9600000.0 | -12600000.0 | -11600000.0 | -11800000.0 | -10900000.0 | -11100000.0 | -11100000.0 | -10600000.0 | -7449000.0 | -6732000.0 | -7106000.0 | -7266000.0 | -5730000.0 | -5167000.0 | -4956000.0 | -4969000.0 | -2085000.0 | -1401000.0 | -1167000.0 | -1466000.0 | -1447000.0 | -842000.0 | -947000.0 |
| Percentage of InterestIncomeExpenseNet | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | -4.3 | -6.0 | -5.8 | -11.0 | -7.6 | -6.2 | -4.1 | -5.2 | -4.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -3.9 | 0.0 | 0.0 | 0.0 | -2.7 | 0.0 | 0.0 | 0.0 | -3.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -0.3 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 20 | 15 | 22 | 17 | 23 | 16 | 21 | 16 | 4.8 | 18 | 5.0 | 17 | 3.9 | 4.6 | 0.764 | 0.816 | 1.156 | 1.571 | 1.978 | 1.04 | 1.314 |
| Percentage of InterestPaidNet | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 4.0 | 4.7 | 8.0 | 5.2 | 12.5 | 6.6 | 7.6 | 5.5 | 1.0 | 7.1 | 2.3 | 8.0 | 0.0 | 0.0 | 0.6 | -0.1 | 0.7 | 0.6 | 1.5 | 0.8 | 0.9 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-05-22 | 2020-06-30 |
| Value | 0.0 | 0.0 | 124 | 124 |
| Percentage of LitigationSettlementExpense | 0.0 | 0.0 | 100.0 | 100.0 |
| Percentage of Revenues | 0.0 | 0.0 | 0.0 | 67.0 |
| Percentage of Revenues chdn:ChurchillDownsIncorporated chdn:CherylKaterVChurchillDownsIncorporated chdn:BigFishGames us-gaap:PendingLitigation | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 108 | 36 | 17 | 43 | -118.8 | -23.4 | 4.0 | 14 | 107 | 11 | 11 | 56 | 103 | 182 | 38 | 16 | 78 | 7.3 | 26 | 8.7 | 69 | 2.8 | 7.508 | 4.203 | 55 | -1.558 | -13.807 | 3.531 | 57 | -0.7 | -5.705 | 9.249 | 50 | 1.058 | 2.374 | 5.973 | 48 | 1.353 | 7.613 | 19 | 40 | -3.185 | -1.895 | -0.689 | 27 |
| Percentage of NetIncomeLoss | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 21.0 | 11.1 | 6.1 | 12.8 | -64.2 | -9.3 | 1.4 | 4.8 | 22.4 | 4.4 | 5.2 | 25.4 | 0.0 | 0.0 | 21.4 | 0.0 | 0.0 | 0.0 | 9.6 | 0.0 | 0.0 | 0.0 | 2.8 | 0.0 | 0.0 | 0.0 | -8.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 17.9 | 1.0 | -1.4 | 11.9 | 16.1 | -2.4 | -1.4 | -0.5 | 12.8 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-06-30 | 2019-03-31 |
| Value | 0 | -100000.0 | 0 | -100000.0 | 0 | 0 |
| Percentage of NetIncomeLossAttributableToNoncontrollingInterest | 0.0 | 100.0 | 0.0 | 100.0 | 0.0 | 0.0 |
| Percentage of Revenues | 0.0 | -0.0 | 0.0 | -0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 |
| Value | 108 | 36 | 17 | 43 | -118.8 | -23.4 | 4.0 | 14 | 107 | 11 | 11 | 56 | 103 | 182 | 38 | 16 | 78 | 7.2 | -1.558 | -13.451 | 3.494 | 56 | -0.7 | -5.294 | 9.054 | 49 | 1.034 | 2.584 | 5.895 | 47 | 1.329 | 7.362 | 19 | 39 |
| Percentage of NetIncomeLossAvailableToCommonStockholdersBasic | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 21.0 | 11.1 | 6.1 | 12.8 | -64.2 | -9.3 | 1.4 | 4.8 | 22.4 | 4.4 | 5.2 | 25.4 | 0.0 | 0.0 | 21.4 | 0.0 | 0.0 | 0.0 | 0.0 | -8.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 17.7 | 1.0 | -1.3 | 11.9 | 15.7 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 |
| Value | 108 | 36 | 17 | 43 | -118.8 | -23.4 | 4.0 | 14 | 107 | 11 | 11 | 56 | 103 | 182 | 38 | 16 | 78 | 7.3 | 26 | 8.7 | 69 | 2.8 | 7.508 | 4.203 | 55 | -1.6 | -13.807 | 3.531 | 57 | -0.7 | -5.705 | 9.249 | 50 | 1.034 | 2.374 | 5.973 | 48 | 7.613 | 19 | 40 |
| Percentage of NetIncomeLossAvailableToCommonStockholdersDiluted | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 21.0 | 11.1 | 6.1 | 12.8 | -64.2 | -9.3 | 1.4 | 4.8 | 22.4 | 4.4 | 5.2 | 25.4 | 0.0 | 0.0 | 21.4 | 0.0 | 0.0 | 0.0 | 9.6 | 0.0 | 0.0 | 0.0 | 2.8 | 0.0 | 0.0 | 0.0 | -8.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 17.9 | -1.4 | 11.9 | 16.1 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 14 | 5.6 | -6.0 | 7.5 | -31.1 | -22.6 | 4.4 | -4.6 | -9.5 | -9.6 | -5.5 | 54 | -0.6 | -3.0 | -29.1 | -4.7 | -3.7 | -5.7 | -6.5 | -6.4 | -5.9 | -7.3 | -4.134 | -4.529 | -4.171 | 1.311 | -5.118 | -3.996 | -2.057 | -2.704 | -4.346 | 2.15 | -0.775 | -1.623 | -1.713 | -0.744 | -1.474 | -1.392 | -1.795 | 18 | 0.213 | -2.351 | -1.691 | -0.233 | -1.334 |
| Percentage of NonoperatingIncomeExpense | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 2.8 | 1.7 | -2.2 | 2.2 | -16.8 | -8.9 | 1.6 | -1.5 | -2.0 | -3.6 | -2.5 | 24.5 | 0.0 | 0.0 | -16.3 | 0.0 | 0.0 | 0.0 | -2.3 | 0.0 | 0.0 | 0.0 | -1.5 | 0.0 | 0.0 | 0.0 | -3.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -0.5 | -1.0 | 0.3 | 10.8 | 0.1 | -1.8 | -1.2 | -0.2 | -0.6 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 |
| Value | 379 | 277 | 255 | 288 | 185 | 264 | 277 | 278 | 321 | 237 | 207 | 200 | 242 | 169 | -129.3 | 281 | 322 | 262 | 234 | 276 | 321 | 282 | 260 | 270 | 303 |
| Percentage of OperatingExpenses | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 73.7 | 85.6 | 91.8 | 85.3 | 100.2 | 104.6 | 98.8 | 90.9 | 67.2 | 89.4 | 94.5 | 90.7 | 0.0 | 0.0 | -72.3 | 0.0 | 0.0 | 0.0 | 84.3 | 0.0 | 0.0 | 0.0 | 95.5 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 135 | 46 | 22 | 49 | -0.4 | -11.6 | 3.5 | 27 | 156 | 28 | 12 | 20 | 136 | 19 | -12.8 | 33 | 129 | 17 | 32 | 26 | 117 | 6.3 | 12 | 9.482 | 105 | -4.128 | -13.703 | 8.373 | 94 | 1.566 | -5.168 | 10 | 82 | 2.993 | 3.036 | 7.813 | 82 | 3.72 | 6.301 | 10 | 67 | -2.853 | -4.27 | 3.295 | 48 |
| Percentage of OperatingIncomeLoss | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 26.3 | 14.4 | 8.2 | 14.7 | -0.2 | -4.6 | 1.2 | 9.1 | 32.8 | 10.6 | 5.5 | 9.3 | 0.0 | 0.0 | -7.2 | 0.0 | 0.0 | 0.0 | 11.6 | 0.0 | 0.0 | 0.0 | 4.5 | 0.0 | 0.0 | 0.0 | -8.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 30.3 | 2.7 | -1.2 | 6.1 | 27.0 | -2.2 | -3.1 | 2.2 | 22.4 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 108 | 36 | 17 | 43 | -118.8 | -23.5 | 3.7 | 14 | 107 | 11 |
| Percentage of ProfitLoss | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 21.0 | 11.1 | 6.1 | 12.8 | -64.2 | -9.3 | 1.3 | 4.8 | 22.4 | 4.4 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 64 | 44 | -17.9 | -3.0 |
| Percentage of ProfitLoss | 59.1 | 122.4 | 15.1 | 12.8 |
| Percentage of Revenues | 12.4 | 13.6 | -9.7 | -1.2 |
| Percentage of Revenues us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees | 32.3 | 31.9 | -263.2 | -2.2 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 108 | 36 | 43 | -118.8 | -23.4 | 14 | 107 | 11 |
| Percentage of ProfitLoss | 100.0 | 100.0 | 100.2 | 100.0 | 99.6 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 21.0 | 11.1 | 12.8 | -64.2 | -9.3 | 4.8 | 22.4 | 4.4 |
| Percentage of Revenues us-gaap:RetainedEarnings | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 515 | 324 | 278 | 337 | 185 | 252 | 280 | 306 | 477 | 265 | 219 | 221 | 0.0 | 0.0 | 178 | 0.0 | 0.0 | 0.0 | 278 | 0.0 | 0.0 | 0.0 | 272 | 0.0 | 0.0 | 0.0 | 168 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 270 | 138 | -547.589 | 166 | 249 | 131 | 137 | 147 | 215 |
| Percentage of Revenues | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 27 | 20 | 17 | 6.5 | 5.7 | 21 | 24 | 24 | 25 | 25 | 23 | 24 | 26 | 24 |
| Percentage of Revenues | 5.3 | 6.4 | 6.4 | 1.9 | 3.1 | 8.6 | 8.7 | 8.0 | 5.4 | 9.6 | 10.8 | 10.8 | 0.0 | 0.0 |
| Percentage of Revenues | 5.3 | 6.4 | 6.4 | 1.9 | 3.1 | 8.6 | 8.7 | 8.0 | 5.4 | 9.6 | 10.8 | 10.8 | 0.0 | 0.0 |
| Percentage of Revenues chdn:CalderCasinos us-gaap:OperatingSegments chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 10 | 34 | 15 | 1.9 | 15 | 8.9 | 161 | 2.3 | 15 | 8.5 | 154 | 2.0 |
| Percentage of Revenues | 3.9 | 10.3 | 8.4 | 0.8 | 5.5 | 2.9 | 33.7 | 0.9 | 7.1 | 3.8 | 0.0 | 0.0 |
| Percentage of Revenues | 3.9 | 10.3 | 8.4 | 0.8 | 5.5 | 2.9 | 33.7 | 0.9 | 7.1 | 3.8 | 0.0 | 0.0 |
| Percentage of Revenues chdn:ChurchillDownsRacetrack us-gaap:OperatingSegments chdn:ChurchillDowns | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 105 | 2.0 | 15 | 1.9 |
| Percentage of Revenues | 20.4 | 0.6 | 8.4 | 0.8 |
| Percentage of Revenues | 20.4 | 0.6 | 8.4 | 0.8 |
| Percentage of Revenues chdn:ChurchillDownsRacetrack us-gaap:OperatingSegments chdn:LiveAndHistoricalRacing | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 24 | 25 | 7.7 | 21 | 24 | 22 | 21 | 18 | 12 | 2.3 | 0.0 | 0.0 |
| Percentage of Revenues | 8.7 | 7.7 | 4.2 | 8.5 | 8.6 | 7.3 | 4.4 | 7.0 | 5.7 | 1.0 | 0.0 | 0.0 |
| Percentage of Revenues | 8.7 | 7.7 | 4.2 | 8.5 | 8.6 | 7.3 | 4.4 | 7.0 | 5.7 | 1.0 | 0.0 | 0.0 |
| Percentage of Revenues chdn:DerbyCityGaming us-gaap:OperatingSegments chdn:ChurchillDowns | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 39 | 32 | 7.7 | 21 |
| Percentage of Revenues | 7.7 | 10.1 | 4.2 | 8.5 |
| Percentage of Revenues | 7.7 | 10.1 | 4.2 | 8.5 |
| Percentage of Revenues chdn:DerbyCityGaming us-gaap:OperatingSegments chdn:LiveAndHistoricalRacing | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 |
| Value | 35 | 38 | 27 | 11 | 31 | 25 | 30 |
| Percentage of Revenues | 6.8 | 11.8 | 8.3 | 6.0 | 12.5 | 8.2 | 6.5 |
| Percentage of Revenues | 6.8 | 11.8 | 8.3 | 6.0 | 12.5 | 8.2 | 6.5 |
| Percentage of Revenues chdn:FairGroundsSlotsFairGroundsRaceCourseAndVideoServicesLLC us-gaap:OperatingSegments chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 16 | 14 | 11 | 13 | 5.6 | 11 | 13 | 13 | 13 | 15 | 12 | 12 | 12 | 13 |
| Percentage of Revenues | 3.2 | 4.3 | 4.1 | 3.8 | 3.0 | 4.6 | 4.8 | 4.3 | 2.8 | 5.8 | 5.6 | 5.5 | 0.0 | 0.0 |
| Percentage of Revenues | 3.2 | 4.3 | 4.1 | 3.8 | 3.0 | 4.6 | 4.8 | 4.3 | 2.8 | 5.8 | 5.6 | 5.5 | 0.0 | 0.0 |
| Percentage of Revenues chdn:HarlowsCasino us-gaap:OperatingSegments chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 127 | 92 | 119 | 66 |
| Percentage of Revenues | 24.7 | 28.6 | 64.8 | 26.3 |
| Percentage of Revenues | 24.7 | 28.6 | 64.8 | 26.3 |
| Percentage of Revenues chdn:HorseRacing us-gaap:OperatingSegments chdn:TwinSpires | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 6.4 | 4.9 | 3.9 | 7.2 | 2.3 | 7.3 | 8.7 | 10.0 | 8.3 | 2.3 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues | 1.2 | 1.5 | 1.4 | 2.1 | 1.2 | 2.9 | 3.1 | 3.3 | 1.7 | 0.9 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues | 1.2 | 1.5 | 1.4 | 2.1 | 1.2 | 2.9 | 3.1 | 3.3 | 1.7 | 0.9 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues chdn:LadyLuckNemacolin us-gaap:OperatingSegments chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 |
| Value | 4.5 | 4.4 |
| Percentage of Revenues | 0.9 | 1.4 |
| Percentage of Revenues | 0.9 | 1.4 |
| Percentage of Revenues chdn:NewportRacingAndGaming us-gaap:OperatingSegments chdn:LiveAndHistoricalRacing | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 |
| Value | 25 | 19 |
| Percentage of Revenues | 5.0 | 6.0 |
| Percentage of Revenues | 5.0 | 6.0 |
| Percentage of Revenues chdn:OakGroveRacingGamingHotel us-gaap:OperatingSegments chdn:LiveAndHistoricalRacing | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 27 | 20 | 18 | 24 | 3.1 | 14 | 18 | 26 | 21 | 18 | 17 | 8.1 | 0.0 | 0.0 |
| Percentage of Revenues | 5.2 | 6.2 | 6.5 | 7.2 | 1.7 | 5.9 | 6.7 | 8.7 | 4.6 | 6.9 | 8.1 | 3.7 | 0.0 | 0.0 |
| Percentage of Revenues | 5.2 | 6.2 | 6.5 | 7.2 | 1.7 | 5.9 | 6.7 | 8.7 | 4.6 | 6.9 | 8.1 | 3.7 | 0.0 | 0.0 |
| Percentage of Revenues chdn:OceanDownsLLCandRacingServicesLLC us-gaap:OperatingSegments chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 1.1 | 1.8 | 1.3 | 0.7 | 0.5 | -0.1 | 0.0 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues | 0.4 | 0.5 | 0.7 | 0.3 | 0.2 | -0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues | 0.4 | 0.5 | 0.7 | 0.3 | 0.2 | -0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues chdn:OnlineSportsBettingAndIGaming us-gaap:OperatingSegments chdn:OnlineWagering | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 24 | 15 | 12 | 12 | 0.1 | 20 | 24 | 27 | 26 | 23 | 22 | 28 | 26 | 24 |
| Percentage of Revenues | 4.8 | 4.8 | 4.5 | 3.6 | 0.1 | 7.9 | 8.7 | 8.9 | 5.5 | 9.0 | 10.4 | 13.1 | 0.0 | 0.0 |
| Percentage of Revenues | 4.8 | 4.8 | 4.5 | 3.6 | 0.1 | 7.9 | 8.7 | 8.9 | 5.5 | 9.0 | 10.4 | 13.1 | 0.0 | 0.0 |
| Percentage of Revenues chdn:OxfordAcquisition us-gaap:OperatingSegments chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 30 | 23 | 17 | 27 | 2.0 | 27 | 33 | 38 | 37 | 29 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues | 5.9 | 7.3 | 6.4 | 8.2 | 1.1 | 10.9 | 12.0 | 12.4 | 7.8 | 11.2 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues | 5.9 | 7.3 | 6.4 | 8.2 | 1.1 | 10.9 | 12.0 | 12.4 | 7.8 | 11.2 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues chdn:PresqueIsleDownsCasino us-gaap:OperatingSegments chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 18 | 14 | 13 | 16 | 7.4 | 12 | 14 | 13 | 14 | 16 | 13 | 12 | 13 | 14 |
| Percentage of Revenues | 3.6 | 4.4 | 4.7 | 4.7 | 4.0 | 5.0 | 5.3 | 4.4 | 3.0 | 6.1 | 6.3 | 5.8 | 0.0 | 0.0 |
| Percentage of Revenues | 3.6 | 4.4 | 4.7 | 4.7 | 4.0 | 5.0 | 5.3 | 4.4 | 3.0 | 6.1 | 6.3 | 5.8 | 0.0 | 0.0 |
| Percentage of Revenues chdn:RiverwalkCasino us-gaap:OperatingSegments chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 8.4 | 7.0 | 1.4 | 2.5 |
| Percentage of Revenues | 1.6 | 2.2 | 0.8 | 1.0 |
| Percentage of Revenues | 1.6 | 2.2 | 0.8 | 1.0 |
| Percentage of Revenues chdn:SportsAndCasino us-gaap:OperatingSegments chdn:TwinSpires | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 0.7 | 4.5 | 0.0 | 4.6 |
| Percentage of Revenues | 0.1 | 1.4 | 0.0 | 1.8 |
| Percentage of Revenues | 0.1 | 1.4 | 0.0 | 1.8 |
| Percentage of Revenues chdn:TurfwayPark us-gaap:OperatingSegments chdn:LiveAndHistoricalRacing | 100.0 | 100.0 | 0.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 92 | 124 | 119 | 66 | 61 | 70 | 95 | 63 | 61 | 71 | 93 | 63 |
| Percentage of Revenues | 33.4 | 36.7 | 64.8 | 26.3 | 21.8 | 23.0 | 20.0 | 23.7 | 28.1 | 32.4 | 0.0 | 0.0 |
| Percentage of Revenues | 33.4 | 36.7 | 64.8 | 26.3 | 21.8 | 23.0 | 20.0 | 23.7 | 28.1 | 32.4 | 0.0 | 0.0 |
| Percentage of Revenues chdn:TwinSpires us-gaap:OperatingSegments chdn:OnlineWagering | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 17 | 3.2 |
| Percentage of Revenues | 3.4 | 1.7 |
| Percentage of Revenues | 3.4 | 1.7 |
| Percentage of Revenues us-gaap:CorporateNonSegment | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 9.4 | 9.8 |
| Percentage of Revenues | 2.9 | 3.9 |
| Percentage of Revenues | 2.9 | 3.9 |
| Percentage of Revenues us-gaap:MaterialReconcilingItems | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 515 | 324 | 278 | 337 | 185 | 252 | 280 | 306 | 477 | 265 | 219 | 221 | 379 | 189 |
| Percentage of Revenues | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 |
| Percentage of Revenues | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 17 | 3.2 |
| Percentage of Revenues | 3.4 | 1.7 |
| Percentage of Revenues | 3.4 | 1.7 |
| Percentage of Revenues us-gaap:CorporateNonSegment chdn:ExternalCustomer | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 9.4 | 9.8 |
| Percentage of Revenues | 2.9 | 3.9 |
| Percentage of Revenues | 2.9 | 3.9 |
| Percentage of Revenues us-gaap:MaterialReconcilingItems chdn:ExternalCustomer | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 497 | 314 | 181 | 243 |
| Percentage of Revenues | 96.6 | 97.1 | 98.3 | 96.1 |
| Percentage of Revenues | 96.6 | 97.1 | 98.3 | 96.1 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 9.5 | 0.8 |
| Percentage of Revenues | 1.8 | 0.4 |
| Percentage of Revenues | 1.8 | 0.4 |
| Percentage of Revenues us-gaap:CorporateNonSegment chdn:ExternalCustomer chdn:PariMutuelLiveAndSimulcastRacing | 100.0 | 100.0 |
| Period End | 2021-06-30 |
| Value | 1.9 |
| Percentage of Revenues | 0.4 |
| Percentage of Revenues | 0.4 |
| Percentage of Revenues us-gaap:CorporateNonSegment chdn:ExternalCustomer chdn:RacingEventRelatedServices | 100.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 6.2 | 2.4 |
| Percentage of Revenues | 1.2 | 1.3 |
| Percentage of Revenues | 1.2 | 1.3 |
| Percentage of Revenues us-gaap:CorporateNonSegment chdn:ExternalCustomer us-gaap:ProductAndServiceOther | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 5.1 | 5.7 |
| Percentage of Revenues | 1.6 | 2.3 |
| Percentage of Revenues | 1.6 | 2.3 |
| Percentage of Revenues us-gaap:MaterialReconcilingItems chdn:ExternalCustomer chdn:PariMutuelLiveAndSimulcastRacing | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 4.3 | 4.0 |
| Percentage of Revenues | 1.3 | 1.6 |
| Percentage of Revenues | 1.3 | 1.6 |
| Percentage of Revenues us-gaap:MaterialReconcilingItems chdn:ExternalCustomer us-gaap:ProductAndServiceOther | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 178 | 139 | 34 | 122 |
| Percentage of Revenues | 34.7 | 43.0 | 18.8 | 48.4 |
| Percentage of Revenues | 34.7 | 43.0 | 18.8 | 48.4 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:Gaming | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 64 | 52 | 7.3 | 20 |
| Percentage of Revenues | 12.6 | 16.3 | 3.9 | 8.1 |
| Percentage of Revenues | 12.6 | 16.3 | 3.9 | 8.1 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:PariMutuelHistoricalRacing | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 165 | 106 | 132 | 79 |
| Percentage of Revenues | 32.1 | 32.9 | 71.4 | 31.2 |
| Percentage of Revenues | 32.1 | 32.9 | 71.4 | 31.2 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:PariMutuelLiveAndSimulcastRacing | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 63 | 0.7 | 1.2 | 1.3 |
| Percentage of Revenues | 12.4 | 0.2 | 0.6 | 0.5 |
| Percentage of Revenues | 12.4 | 0.2 | 0.6 | 0.5 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:RacingEventRelatedServices | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 24 | 15 | 6.4 | 20 |
| Percentage of Revenues | 4.8 | 4.6 | 3.5 | 7.9 |
| Percentage of Revenues | 4.8 | 4.6 | 3.5 | 7.9 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer us-gaap:ProductAndServiceOther | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 2.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues | 0.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues | 0.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:MaterialReconcilingItems chdn:ExternalCustomer chdn:PariMutuelHistoricalRacing us-gaap:AllOtherSegments | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 9.0 | 0.8 | 9.9 | 6.4 | 15 | 12 | 7.5 | 5.0 | 16 | 13 | 7.9 |
| Percentage of Revenues | 2.7 | 0.4 | 3.9 | 2.3 | 4.9 | 2.6 | 2.8 | 2.3 | 7.5 | 0.0 | 0.0 |
| Percentage of Revenues | 2.7 | 0.4 | 3.9 | 2.3 | 4.9 | 2.6 | 2.8 | 2.3 | 7.5 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:MaterialReconcilingItems chdn:ExternalCustomer chdn:PariMutuelLiveAndSimulcastRacing us-gaap:AllOtherSegments | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 0.2 | 0.0 | 0.1 | 0.3 | 3.1 | 2.2 | 0.0 | 0.1 | 3.5 | 2.2 | 0.0 |
| Percentage of Revenues | 0.1 | 0.0 | 0.0 | 0.1 | 1.0 | 0.5 | 0.0 | 0.0 | 1.6 | 0.0 | 0.0 |
| Percentage of Revenues | 0.1 | 0.0 | 0.0 | 0.1 | 1.0 | 0.5 | 0.0 | 0.0 | 1.6 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:MaterialReconcilingItems chdn:ExternalCustomer chdn:RacingEventRelatedServices us-gaap:AllOtherSegments | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 4.9 | 2.5 | 4.5 | 5.0 | 8.3 | 7.6 | 5.0 | 4.8 | 8.2 | 6.9 | 4.7 |
| Percentage of Revenues | 1.5 | 1.4 | 1.8 | 1.8 | 2.7 | 1.6 | 1.9 | 2.2 | 3.7 | 0.0 | 0.0 |
| Percentage of Revenues | 1.5 | 1.4 | 1.8 | 1.8 | 2.7 | 1.6 | 1.9 | 2.2 | 3.7 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:MaterialReconcilingItems chdn:ExternalCustomer us-gaap:ProductAndServiceOther us-gaap:AllOtherSegments | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 170 | 132 | 109 | 123 | 33 | 121 | 142 | 153 | 150 | 146 | 98 | 92 | 87 | 93 |
| Percentage of Revenues | 33.0 | 40.9 | 39.2 | 36.6 | 18.0 | 48.1 | 50.9 | 50.0 | 31.5 | 55.2 | 44.8 | 41.9 | 0.0 | 0.0 |
| Percentage of Revenues | 33.0 | 40.9 | 39.2 | 36.6 | 18.0 | 48.1 | 50.9 | 50.0 | 31.5 | 55.2 | 44.8 | 41.9 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:Gaming chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 1.3 | 1.6 | 1.5 | 0.7 | 0.5 | 0.0 | 0.0 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues | 0.5 | 0.5 | 0.8 | 0.3 | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues | 0.5 | 0.5 | 0.8 | 0.3 | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:Gaming chdn:OnlineWagering | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 8.4 | 7.0 | 1.4 | 2.5 |
| Percentage of Revenues | 1.6 | 2.2 | 0.8 | 1.0 |
| Percentage of Revenues | 1.6 | 2.2 | 0.8 | 1.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:Gaming chdn:TwinSpires | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 125 | 34 | 122 | 143 | 153 | 150 | 146 | 98 | 92 | 87 | 93 |
| Percentage of Revenues | 37.1 | 18.8 | 48.4 | 51.1 | 50.0 | 31.5 | 55.3 | 44.8 | 41.9 | 0.0 | 0.0 |
| Percentage of Revenues | 37.1 | 18.8 | 48.4 | 51.1 | 50.0 | 31.5 | 55.3 | 44.8 | 41.9 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:Gaming us-gaap:Corporate | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 23 | 24 | 7.3 | 20 | 22 | 21 | 19 | 17 | 11 | 2.2 | 0.0 | 0.0 |
| Percentage of Revenues | 8.4 | 7.4 | 3.9 | 8.1 | 8.2 | 7.0 | 4.2 | 6.7 | 5.3 | 1.0 | 0.0 | 0.0 |
| Percentage of Revenues | 8.4 | 7.4 | 3.9 | 8.1 | 8.2 | 7.0 | 4.2 | 6.7 | 5.3 | 1.0 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:PariMutuelHistoricalRacing chdn:ChurchillDowns | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 64 | 52 | 7.3 | 20 |
| Percentage of Revenues | 12.6 | 16.3 | 3.9 | 8.1 |
| Percentage of Revenues | 12.6 | 16.3 | 3.9 | 8.1 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:PariMutuelHistoricalRacing chdn:LiveAndHistoricalRacing | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 24 | 7.3 | 20 | 22 | 21 | 19 | 17 | 11 | 2.2 | 0.0 | 0.0 |
| Percentage of Revenues | 7.4 | 3.9 | 8.1 | 8.2 | 7.0 | 4.2 | 6.7 | 5.3 | 1.0 | 0.0 | 0.0 |
| Percentage of Revenues | 7.4 | 3.9 | 8.1 | 8.2 | 7.0 | 4.2 | 6.7 | 5.3 | 1.0 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:PariMutuelHistoricalRacing us-gaap:Corporate | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 9.2 | 14 | 14 | 1.0 | 10 | 5.4 | 41 | 1.4 | 9.3 | 4.8 | 39 | 1.3 |
| Percentage of Revenues | 3.3 | 4.2 | 8.0 | 0.4 | 3.9 | 1.8 | 8.7 | 0.5 | 4.2 | 2.2 | 0.0 | 0.0 |
| Percentage of Revenues | 3.3 | 4.2 | 8.0 | 0.4 | 3.9 | 1.8 | 8.7 | 0.5 | 4.2 | 2.2 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:PariMutuelLiveAndSimulcastRacing chdn:ChurchillDowns | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 4.4 | 11 | 6.7 | 4.6 | 1.7 | 9.9 | 6.8 | 6.2 | 5.5 | 12 | 7.8 | 4.3 | 4.4 | 10 |
| Percentage of Revenues | 0.9 | 3.6 | 2.4 | 1.4 | 0.9 | 3.9 | 2.4 | 2.0 | 1.2 | 4.6 | 3.6 | 1.9 | 0.0 | 0.0 |
| Percentage of Revenues | 0.9 | 3.6 | 2.4 | 1.4 | 0.9 | 3.9 | 2.4 | 2.0 | 1.2 | 4.6 | 3.6 | 1.9 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:PariMutuelLiveAndSimulcastRacing chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 39 | 5.9 | 14 | 5.2 |
| Percentage of Revenues | 7.7 | 1.8 | 8.0 | 2.1 |
| Percentage of Revenues | 7.7 | 1.8 | 8.0 | 2.1 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:PariMutuelLiveAndSimulcastRacing chdn:LiveAndHistoricalRacing | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 89 | 119 | 115 | 63 | 58 | 67 | 91 | 60 | 58 | 68 | 89 | 61 |
| Percentage of Revenues | 32.0 | 35.2 | 62.5 | 25.3 | 20.8 | 21.9 | 19.1 | 22.8 | 26.9 | 31.1 | 0.0 | 0.0 |
| Percentage of Revenues | 32.0 | 35.2 | 62.5 | 25.3 | 20.8 | 21.9 | 19.1 | 22.8 | 26.9 | 31.1 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:PariMutuelLiveAndSimulcastRacing chdn:OnlineWagering | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 121 | 89 | 115 | 63 |
| Percentage of Revenues | 23.6 | 27.5 | 62.5 | 25.3 |
| Percentage of Revenues | 23.6 | 27.5 | 62.5 | 25.3 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:PariMutuelLiveAndSimulcastRacing chdn:TwinSpires | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 137 | 132 | 74 | 76 | 78 | 137 | 74 | 76 | 77 | 133 | 72 |
| Percentage of Revenues | 40.8 | 71.4 | 29.6 | 27.1 | 25.7 | 28.9 | 27.9 | 34.7 | 35.2 | 0.0 | 0.0 |
| Percentage of Revenues | 40.8 | 71.4 | 29.6 | 27.1 | 25.7 | 28.9 | 27.9 | 34.7 | 35.2 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:PariMutuelLiveAndSimulcastRacing us-gaap:Corporate | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 1.4 | 19 | 0.5 | 0.0 | 3.7 | 1.6 | 113 | 0.0 | 3.6 | 2.0 | 109 | 0.0 |
| Percentage of Revenues | 0.5 | 5.7 | 0.3 | 0.0 | 1.3 | 0.5 | 23.8 | 0.0 | 1.6 | 0.9 | 0.0 | 0.0 |
| Percentage of Revenues | 0.5 | 5.7 | 0.3 | 0.0 | 1.3 | 0.5 | 23.8 | 0.0 | 1.6 | 0.9 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:RacingEventRelatedServices chdn:ChurchillDowns | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 0.2 | 0.7 | 0.7 | 0.7 | 0.7 | 1.3 | 1.0 | 0.8 | 0.8 | 1.5 | 1.0 | 0.8 | 0.7 | 1.4 |
| Percentage of Revenues | 0.0 | 0.2 | 0.3 | 0.2 | 0.4 | 0.5 | 0.4 | 0.3 | 0.2 | 0.6 | 0.5 | 0.4 | 0.0 | 0.0 |
| Percentage of Revenues | 0.0 | 0.2 | 0.3 | 0.2 | 0.4 | 0.5 | 0.4 | 0.3 | 0.2 | 0.6 | 0.5 | 0.4 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:RacingEventRelatedServices chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 63 | 0.5 |
| Percentage of Revenues | 12.3 | 0.3 |
| Percentage of Revenues | 12.3 | 0.3 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:RacingEventRelatedServices chdn:LiveAndHistoricalRacing | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 19 | 1.2 | 1.3 | 4.7 | 2.4 | 114 | 1.5 | 4.6 | 2.8 | 110 | 1.4 |
| Percentage of Revenues | 5.9 | 0.6 | 0.5 | 1.7 | 0.8 | 23.9 | 0.6 | 2.1 | 1.3 | 0.0 | 0.0 |
| Percentage of Revenues | 5.9 | 0.6 | 0.5 | 1.7 | 0.8 | 23.9 | 0.6 | 2.1 | 1.3 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:RacingEventRelatedServices us-gaap:Corporate | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 1.2 | 2.5 | 0.6 | 2.1 | 2.1 | 3.1 | 7.6 | 1.9 | 3.6 | 1.8 | 5.8 | 0.7 |
| Percentage of Revenues | 0.4 | 0.7 | 0.3 | 0.8 | 0.7 | 1.0 | 1.6 | 0.7 | 1.6 | 0.8 | 0.0 | 0.0 |
| Percentage of Revenues | 0.4 | 0.7 | 0.3 | 0.8 | 0.7 | 1.0 | 1.6 | 0.7 | 1.6 | 0.8 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer us-gaap:ProductAndServiceOther chdn:ChurchillDowns | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 11 | 7.1 | 5.3 | 5.9 | 1.6 | 14 | 17 | 18 | 21 | 8.5 | 12 | 12 | 15 | 5.6 |
| Percentage of Revenues | 2.2 | 2.2 | 1.9 | 1.7 | 0.9 | 5.9 | 6.1 | 5.9 | 4.4 | 3.2 | 5.8 | 5.6 | 0.0 | 0.0 |
| Percentage of Revenues | 2.2 | 2.2 | 1.9 | 1.7 | 0.9 | 5.9 | 6.1 | 5.9 | 4.4 | 3.2 | 5.8 | 5.6 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer us-gaap:ProductAndServiceOther chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 7.9 | 4.4 | 0.6 | 2.5 |
| Percentage of Revenues | 1.5 | 1.4 | 0.3 | 1.0 |
| Percentage of Revenues | 1.5 | 1.4 | 0.3 | 1.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer us-gaap:ProductAndServiceOther chdn:LiveAndHistoricalRacing | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 3.6 | 5.3 | 4.1 | 2.7 | 2.7 | 3.1 | 4.5 | 2.5 | 2.6 | 3.0 | 4.0 | 2.2 |
| Percentage of Revenues | 1.3 | 1.6 | 2.2 | 1.1 | 1.0 | 1.0 | 0.9 | 0.9 | 1.2 | 1.4 | 0.0 | 0.0 |
| Percentage of Revenues | 1.3 | 1.6 | 2.2 | 1.1 | 1.0 | 1.0 | 0.9 | 0.9 | 1.2 | 1.4 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer us-gaap:ProductAndServiceOther chdn:OnlineWagering | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 5.6 | 3.5 | 4.3 | 2.7 |
| Percentage of Revenues | 1.1 | 1.1 | 2.3 | 1.1 |
| Percentage of Revenues | 1.1 | 1.1 | 2.3 | 1.1 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer us-gaap:ProductAndServiceOther chdn:TwinSpires | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 13 | 6.3 | 19 | 21 | 24 | 33 | 12 | 18 | 17 | 25 | 8.5 |
| Percentage of Revenues | 4.1 | 3.4 | 7.8 | 7.8 | 7.9 | 7.0 | 4.9 | 8.6 | 7.8 | 0.0 | 0.0 |
| Percentage of Revenues | 4.1 | 3.4 | 7.8 | 7.8 | 7.9 | 7.0 | 4.9 | 8.6 | 7.8 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer us-gaap:ProductAndServiceOther us-gaap:Corporate | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 16 | 3.3 | 14 | 11 | 26 | 22 | 12 | 9.9 | 28 | 22 | 12 |
| Percentage of Revenues | 4.8 | 1.8 | 5.7 | 4.2 | 8.6 | 4.6 | 4.7 | 4.5 | 12.8 | 0.0 | 0.0 |
| Percentage of Revenues | 4.8 | 1.8 | 5.7 | 4.2 | 8.6 | 4.6 | 4.7 | 4.5 | 12.8 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:MaterialReconcilingItems chdn:ExternalCustomer us-gaap:AllOtherSegments | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 35 | 60 | 23 | 23 | 39 | 31 | 182 | 21 | 28 | 10 | 154 | 2.0 |
| Percentage of Revenues | 12.7 | 18.0 | 12.6 | 9.3 | 14.1 | 10.3 | 38.2 | 7.9 | 12.8 | 4.9 | 0.0 | 0.0 |
| Percentage of Revenues | 12.7 | 18.0 | 12.6 | 9.3 | 14.1 | 10.3 | 38.2 | 7.9 | 12.8 | 4.9 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:ChurchillDowns | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 186 | 152 | 121 | 134 | 37 | 147 | 167 | 178 | 177 | 168 | 119 | 110 | 108 | 111 |
| Percentage of Revenues | 36.1 | 46.9 | 43.7 | 39.9 | 20.2 | 58.4 | 59.8 | 58.2 | 37.2 | 63.6 | 54.6 | 49.9 | 0.0 | 0.0 |
| Percentage of Revenues | 36.1 | 46.9 | 43.7 | 39.9 | 20.2 | 58.4 | 59.8 | 58.2 | 37.2 | 63.6 | 54.6 | 49.9 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 175 | 63 | 23 | 28 |
| Percentage of Revenues | 34.1 | 19.5 | 12.6 | 11.1 |
| Percentage of Revenues | 34.1 | 19.5 | 12.6 | 11.1 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:LiveAndHistoricalRacing | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 93 | 125 | 121 | 67 | 61 | 70 | 95 | 63 | 61 | 71 | 93 | 63 |
| Percentage of Revenues | 33.8 | 37.3 | 65.5 | 26.6 | 22.0 | 22.9 | 20.0 | 23.8 | 28.1 | 32.4 | 0.0 | 0.0 |
| Percentage of Revenues | 33.8 | 37.3 | 65.5 | 26.6 | 22.0 | 22.9 | 20.0 | 23.8 | 28.1 | 32.4 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:OnlineWagering | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 135 | 99 | 121 | 69 |
| Percentage of Revenues | 26.3 | 30.7 | 65.5 | 27.3 |
| Percentage of Revenues | 26.3 | 30.7 | 65.5 | 27.3 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer chdn:TwinSpires | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 321 | 181 | 238 | 268 | 279 | 455 | 252 | 209 | 193 | 356 | 176 |
| Percentage of Revenues | 95.2 | 98.2 | 94.3 | 95.8 | 91.4 | 95.4 | 95.3 | 95.5 | 87.2 | 0.0 | 0.0 |
| Percentage of Revenues | 95.2 | 98.2 | 94.3 | 95.8 | 91.4 | 95.4 | 95.3 | 95.5 | 87.2 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ExternalCustomer us-gaap:Corporate | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 16 | 3.3 | 14 | 11 | 26 | 22 | 12 | 9.9 | 28 | 22 | 12 |
| Percentage of Revenues | 4.8 | 1.8 | 5.7 | 4.2 | 8.6 | 4.6 | 4.7 | 4.5 | 12.8 | 0.0 | 0.0 |
| Percentage of Revenues | 4.8 | 1.8 | 5.7 | 4.2 | 8.6 | 4.6 | 4.7 | 4.5 | 12.8 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:MaterialReconcilingItems us-gaap:AllOtherSegments | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 35 | 60 | 23 | 23 | 39 | 31 | 182 | 21 | 28 | 10 | 154 | 2.0 |
| Percentage of Revenues | 12.7 | 18.0 | 12.6 | 9.3 | 14.1 | 10.3 | 38.2 | 7.9 | 12.8 | 4.9 | 0.0 | 0.0 |
| Percentage of Revenues | 12.7 | 18.0 | 12.6 | 9.3 | 14.1 | 10.3 | 38.2 | 7.9 | 12.8 | 4.9 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:ChurchillDowns | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 186 | 152 | 121 | 134 | 37 | 147 | 167 | 178 | 177 | 168 | 119 | 110 | 108 | 111 |
| Percentage of Revenues | 36.1 | 46.9 | 43.7 | 39.9 | 20.2 | 58.4 | 59.8 | 58.2 | 37.2 | 63.6 | 54.6 | 49.9 | 0.0 | 0.0 |
| Percentage of Revenues | 36.1 | 46.9 | 43.7 | 39.9 | 20.2 | 58.4 | 59.8 | 58.2 | 37.2 | 63.6 | 54.6 | 49.9 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 175 | 63 | 23 | 28 |
| Percentage of Revenues | 34.1 | 19.5 | 12.6 | 11.1 |
| Percentage of Revenues | 34.1 | 19.5 | 12.6 | 11.1 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:LiveAndHistoricalRacing | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 93 | 125 | 121 | 67 | 61 | 70 | 95 | 63 | 62 | 71 | 93 | 63 |
| Percentage of Revenues | 33.8 | 37.3 | 65.5 | 26.6 | 22.0 | 22.9 | 20.0 | 23.8 | 28.7 | 32.4 | 0.0 | 0.0 |
| Percentage of Revenues | 33.8 | 37.3 | 65.5 | 26.6 | 22.0 | 22.9 | 20.0 | 23.8 | 28.7 | 32.4 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:OnlineWagering | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 135 | 99 | 121 | 69 |
| Percentage of Revenues | 26.3 | 30.7 | 65.5 | 27.3 |
| Percentage of Revenues | 26.3 | 30.7 | 65.5 | 27.3 |
| Percentage of Revenues us-gaap:OperatingSegments chdn:TwinSpires | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 197 | 138 | 6.8 | 137 |
| Percentage of Revenues | 38.4 | 42.8 | 3.7 | 54.5 |
| Percentage of Revenues | 38.4 | 42.8 | 3.7 | 54.5 |
| Percentage of Revenues us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 515 | 324 | 278 | 337 | 185 | 252 | 280 | 306 | 477 | 265 | 219 | 221 | 379 | 189 |
| Percentage of Revenues | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 |
| Percentage of Revenues | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 |
| Percentage of Revenues chdn:ExternalCustomer | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 178 | 139 | 110 | 125 | 34 | 122 | 143 | 153 | 150 | 146 | 98 | 92 | 87 | 93 |
| Percentage of Revenues | 34.7 | 43.0 | 39.6 | 37.1 | 18.8 | 48.4 | 51.1 | 50.0 | 31.5 | 55.3 | 44.8 | 41.9 | 0.0 | 0.0 |
| Percentage of Revenues | 34.7 | 43.0 | 39.6 | 37.1 | 18.8 | 48.4 | 51.1 | 50.0 | 31.5 | 55.3 | 44.8 | 41.9 | 0.0 | 0.0 |
| Percentage of Revenues chdn:ExternalCustomer chdn:Gaming | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 64 | 52 | 38 | 27 | 7.3 | 20 | 22 | 21 | 19 | 17 | 11 | 2.2 | 0.0 | 0.0 |
| Percentage of Revenues | 12.6 | 16.3 | 13.9 | 8.0 | 3.9 | 8.1 | 8.2 | 7.0 | 4.2 | 6.7 | 5.3 | 1.0 | 0.0 | 0.0 |
| Percentage of Revenues | 12.6 | 16.3 | 13.9 | 8.0 | 3.9 | 8.1 | 8.2 | 7.0 | 4.2 | 6.7 | 5.3 | 1.0 | 0.0 | 0.0 |
| Percentage of Revenues chdn:ExternalCustomer chdn:PariMutuelHistoricalRacing | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 175 | 111 | 110 | 146 | 133 | 84 | 82 | 93 | 150 | 81 | 81 | 94 | 147 | 80 |
| Percentage of Revenues | 34.0 | 34.5 | 39.7 | 43.5 | 71.9 | 33.5 | 29.4 | 30.6 | 31.4 | 30.7 | 37.0 | 42.7 | 0.0 | 0.0 |
| Percentage of Revenues | 34.0 | 34.5 | 39.7 | 43.5 | 71.9 | 33.5 | 29.4 | 30.6 | 31.4 | 30.7 | 37.0 | 42.7 | 0.0 | 0.0 |
| Percentage of Revenues chdn:ExternalCustomer chdn:PariMutuelLiveAndSimulcastRacing | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 65 | 0.7 | 2.1 | 20 | 1.2 | 1.4 | 5.0 | 5.5 | 116 | 1.5 | 4.7 | 6.3 | 112 | 1.4 |
| Percentage of Revenues | 12.7 | 0.2 | 0.8 | 5.9 | 0.6 | 0.6 | 1.8 | 1.8 | 24.4 | 0.6 | 2.1 | 2.8 | 0.0 | 0.0 |
| Percentage of Revenues | 12.7 | 0.2 | 0.8 | 5.9 | 0.6 | 0.6 | 1.8 | 1.8 | 24.4 | 0.6 | 2.1 | 2.8 | 0.0 | 0.0 |
| Percentage of Revenues chdn:ExternalCustomer chdn:RacingEventRelatedServices | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 30 | 19 | 16 | 18 | 8.8 | 24 | 26 | 32 | 40 | 17 | 23 | 25 | 32 | 13 |
| Percentage of Revenues | 6.0 | 6.0 | 5.9 | 5.5 | 4.8 | 9.5 | 9.6 | 10.6 | 8.5 | 6.7 | 10.8 | 11.5 | 0.0 | 0.0 |
| Percentage of Revenues | 6.0 | 6.0 | 5.9 | 5.5 | 4.8 | 9.5 | 9.6 | 10.6 | 8.5 | 6.7 | 10.8 | 11.5 | 0.0 | 0.0 |
| Percentage of Revenues chdn:ExternalCustomer us-gaap:ProductAndServiceOther | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 35 | 60 | 23 | 39 | 31 | 182 | 21 | 28 | 10 | 154 | 2.0 |
| Percentage of Revenues | 12.7 | 18.0 | 12.6 | 14.1 | 10.3 | 38.2 | 7.9 | 12.8 | 4.9 | 0.0 | 0.0 |
| Percentage of Revenues | 12.7 | 18.0 | 12.6 | 14.1 | 10.3 | 38.2 | 7.9 | 12.8 | 4.9 | 0.0 | 0.0 |
| Percentage of Revenues chdn:ChurchillDowns | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 186 | 152 | 121 | 134 | 37 | 145 | 167 | 178 | 177 | 168 | 119 | 110 | 108 | 111 |
| Percentage of Revenues | 36.1 | 46.9 | 43.7 | 39.9 | 20.2 | 57.7 | 59.8 | 58.2 | 37.2 | 63.6 | 54.6 | 49.9 | 0.0 | 0.0 |
| Percentage of Revenues | 36.1 | 46.9 | 43.7 | 39.9 | 20.2 | 57.7 | 59.8 | 58.2 | 37.2 | 63.6 | 54.6 | 49.9 | 0.0 | 0.0 |
| Percentage of Revenues chdn:Gaming | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 175 | 63 | 23 | 28 |
| Percentage of Revenues | 34.1 | 19.5 | 12.6 | 11.1 |
| Percentage of Revenues | 34.1 | 19.5 | 12.6 | 11.1 |
| Percentage of Revenues chdn:LiveAndHistoricalRacing | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 93 | 125 | 121 | 61 | 70 | 95 | 63 | 61 | 71 | 93 | 63 |
| Percentage of Revenues | 33.8 | 37.3 | 65.5 | 22.0 | 22.9 | 20.0 | 23.8 | 28.1 | 32.4 | 0.0 | 0.0 |
| Percentage of Revenues | 33.8 | 37.3 | 65.5 | 22.0 | 22.9 | 20.0 | 23.8 | 28.1 | 32.4 | 0.0 | 0.0 |
| Percentage of Revenues chdn:OnlineWagering | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 135 | 99 | 121 | 69 |
| Percentage of Revenues | 26.3 | 30.7 | 65.5 | 27.3 |
| Percentage of Revenues | 26.3 | 30.7 | 65.5 | 27.3 |
| Percentage of Revenues chdn:TwinSpires | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 17 | 9.4 | 27 | 16 | 3.3 | 9.8 | 11 | 26 | 22 | 12 | 9.9 | 28 | 22 | 12 |
| Percentage of Revenues | 3.4 | 2.9 | 9.8 | 4.8 | 1.8 | 3.9 | 4.2 | 8.6 | 4.6 | 4.7 | 4.5 | 12.8 | 0.0 | 0.0 |
| Percentage of Revenues | 3.4 | 2.9 | 9.8 | 4.8 | 1.8 | 3.9 | 4.2 | 8.6 | 4.6 | 4.7 | 4.5 | 12.8 | 0.0 | 0.0 |
| Percentage of Revenues us-gaap:ProductAndServiceOther | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 38 | 68 | 30 | 23 | 42 | 32 | 193 | 21 | 30 | 11 | 164 | 2.3 |
| Percentage of Revenues | 13.8 | 20.1 | 16.3 | 9.4 | 15.0 | 10.7 | 40.4 | 8.1 | 13.7 | 5.3 | 0.0 | 0.0 |
| Percentage of Revenues | 13.8 | 20.1 | 16.3 | 9.4 | 15.0 | 10.7 | 40.4 | 8.1 | 13.7 | 5.3 | 0.0 | 0.0 |
| Percentage of Revenues chdn:ChurchillDowns | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 186 | 154 | 122 | 134 | 37 | 149 | 168 | 178 | 177 | 170 | 120 | 110 | 108 | 112 |
| Percentage of Revenues | 36.1 | 47.5 | 44.1 | 39.9 | 20.2 | 59.0 | 60.0 | 58.3 | 37.2 | 64.1 | 54.8 | 49.9 | 0.0 | 0.0 |
| Percentage of Revenues | 36.1 | 47.5 | 44.1 | 39.9 | 20.2 | 59.0 | 60.0 | 58.3 | 37.2 | 64.1 | 54.8 | 49.9 | 0.0 | 0.0 |
| Percentage of Revenues chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 190 | 64 | 30 | 29 |
| Percentage of Revenues | 37.0 | 20.0 | 16.4 | 11.5 |
| Percentage of Revenues | 37.0 | 20.0 | 16.4 | 11.5 |
| Percentage of Revenues chdn:LiveAndHistoricalRacing | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 94 | 126 | 121 | 67 | 61 | 70 | 96 | 63 | 60 | 72 | 94 | 63 |
| Percentage of Revenues | 33.9 | 37.4 | 65.7 | 26.8 | 22.0 | 23.0 | 20.1 | 23.9 | 27.6 | 32.6 | 0.0 | 0.0 |
| Percentage of Revenues | 33.9 | 37.4 | 65.7 | 26.8 | 22.0 | 23.0 | 20.1 | 23.9 | 27.6 | 32.6 | 0.0 | 0.0 |
| Percentage of Revenues chdn:OnlineWagering | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 |
| Value | 135 | 100 | 121 | 69 | 72 | 0.4 | 0.4 | 0.2 | 0.3 | 0.3 | 0.4 | 0.3 | 0.3 | 0.251 | 0.234 | 0.25 | 0.297 | 0.244 | 0.24 | 0.244 | 0.23 |
| Percentage of Revenues | 26.4 | 30.9 | 65.7 | 27.4 | 32.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 0.0 | 0.0 | 0.0 | 0.1 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues | 26.4 | 30.9 | 65.7 | 27.4 | 32.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 0.0 | 0.0 | 0.0 | 0.1 | 0.0 | 0.0 | 0.0 |
| Percentage of Revenues chdn:TwinSpires | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 33 | 30 | 29 | 38 | 22 | 24 | 32 | 34 | 30 | 24 | 27 | 21 | 23 | 18 | 5.5 | 26 | 26 | 24 | 24 | 27 | 24 | 23 | 22 | 24 | 22 | 21 | 24 | 20 | 18 | 21 | 22 | 21 | 22 | 17 | 19 | 18 | 20 | 16 | 14 | 16 | 18 | 16 | 18 | 15 | 15 |
| Percentage of SellingGeneralAndAdministrativeExpense | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 6.5 | 9.3 | 10.6 | 11.5 | 12.1 | 9.5 | 11.6 | 11.2 | 6.3 | 9.4 | 12.5 | 9.8 | 0.0 | 0.0 | 3.1 | 0.0 | 0.0 | 0.0 | 8.9 | 0.0 | 0.0 | 0.0 | 8.3 | 0.0 | 0.0 | 0.0 | 14.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 7.4 | 11.7 | -2.6 | 9.7 | 7.3 | 12.2 | 13.5 | 10.4 | 7.3 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 2970 | 2787 | 2686 | 3263 | 3216 | 3203 | 2551 | 2562 | 2588 | 2478 | 1725 | 1711 | 1696 | 1601 | 2359 | 2327 | 2282 | 2256 | 2254 | 2224 | 2248 | 2238 | 2277 | 2260 | 2298 | 2302 | 2360 | 1332 | 1363 | 1351 | 1352 | 1287 | 1129 | 1097 | 1114 | 939 | 959 | 937 | 948 | 956 | 998 | 1017 |
| Percentage of Assets | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 37 |
| Percentage of Assets | 1.4 |
| Percentage of Assets | 1.4 |
| Percentage of Assets chdn:NewportRacingAndGaming chdn:LiveAndHistoricalRacing | 100.0 |
| Period End | 2020-12-31 |
| Value | 196 |
| Percentage of Assets | 7.3 |
| Percentage of Assets | 7.3 |
| Percentage of Assets chdn:OakGroveRacingGamingHotel chdn:LiveAndHistoricalRacing | 100.0 |
| Period End | 2020-12-31 |
| Value | 52 |
| Percentage of Assets | 1.9 |
| Percentage of Assets | 1.9 |
| Percentage of Assets chdn:TurfwayPark chdn:LiveAndHistoricalRacing | 100.0 |
| Period End | 2021-06-30 | 2020-12-31 | 2019-12-31 |
| Value | 1072 | 1102 | 909 |
| Percentage of Assets | 36.1 | 41.0 | 35.6 |
| Percentage of Assets | 36.1 | 41.0 | 35.6 |
| Percentage of Assets us-gaap:CorporateNonSegment | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2020-12-31 | 2019-12-31 |
| Value | 1898 | 1584 | 1641 |
| Percentage of Assets | 63.9 | 59.0 | 64.4 |
| Percentage of Assets | 63.9 | 59.0 | 64.4 |
| Percentage of Assets us-gaap:OperatingSegments | 100.0 | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 99 | 1646 | 1625 | 1650 | 909 | 348 | 367 | 269 | 265 |
| Percentage of Assets | 3.6 | 50.5 | 50.5 | 51.5 | 35.6 | 13.6 | 14.2 | 10.9 | 15.4 |
| Percentage of Assets | 3.6 | 50.5 | 50.5 | 51.5 | 35.6 | 13.6 | 14.2 | 10.9 | 15.4 |
| Percentage of Assets us-gaap:MaterialReconcilingItems us-gaap:AllOtherSegments | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 377 | 394 | 395 | 369 | 370 | 364 | 371 | 367 | 359 |
| Percentage of Assets | 14.1 | 12.1 | 12.3 | 11.5 | 14.5 | 14.2 | 14.3 | 14.8 | 20.8 |
| Percentage of Assets | 14.1 | 12.1 | 12.3 | 11.5 | 14.5 | 14.2 | 14.3 | 14.8 | 20.8 |
| Percentage of Assets us-gaap:OperatingSegments chdn:ChurchillDowns | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 |
| Value | 964 | 949 | 968 | 945 | 940 | 1030 |
| Percentage of Assets | 32.5 | 35.3 | 29.7 | 29.4 | 29.3 | 40.4 |
| Percentage of Assets | 32.5 | 35.3 | 29.7 | 29.4 | 29.3 | 40.4 |
| Percentage of Assets us-gaap:OperatingSegments chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2020-12-31 |
| Value | 653 | 664 |
| Percentage of Assets | 22.0 | 24.7 |
| Percentage of Assets | 22.0 | 24.7 |
| Percentage of Assets us-gaap:OperatingSegments chdn:LiveAndHistoricalRacing | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 249 | 253 | 250 | 243 | 241 | 242 | 244 | 237 | 222 |
| Percentage of Assets | 9.3 | 7.8 | 7.8 | 7.6 | 9.5 | 9.5 | 9.4 | 9.6 | 12.9 |
| Percentage of Assets | 9.3 | 7.8 | 7.8 | 7.6 | 9.5 | 9.5 | 9.4 | 9.6 | 12.9 |
| Percentage of Assets us-gaap:OperatingSegments chdn:OnlineWagering | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2020-12-31 |
| Value | 280 | 257 |
| Percentage of Assets | 9.4 | 9.6 |
| Percentage of Assets | 9.4 | 9.6 |
| Percentage of Assets us-gaap:OperatingSegments chdn:TwinSpires | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 1616 | 1590 | 1553 | 1641 | 2213 | 2221 | 2208 | 1459 |
| Percentage of Assets | 49.5 | 49.5 | 48.5 | 64.4 | 86.4 | 85.8 | 89.1 | 84.6 |
| Percentage of Assets | 49.5 | 49.5 | 48.5 | 64.4 | 86.4 | 85.8 | 89.1 | 84.6 |
| Percentage of Assets us-gaap:OperatingSegments us-gaap:Corporate | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2019-12-31 |
| Value | 620 | 599 | 645 | 560 |
| Percentage of Assets | 20.9 | 21.5 | 24.0 | 22.0 |
| Percentage of Assets | 20.9 | 21.5 | 24.0 | 22.0 |
| Percentage of Assets us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2018-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 |
| Value | 957 | 1030 | 1606 | 1605 | 877 | 618 | 617 | 621 | 535 | 535 | 372 | 222 | 225 | 214 | 215 | 242 |
| Percentage of Assets | 35.6 | 40.4 | 62.7 | 62.0 | 50.8 | 46.4 | 45.3 | 46.0 | 39.6 | 41.6 | 33.0 | 20.3 | 20.3 | 22.9 | 22.4 | 25.5 |
| Percentage of Assets | 35.6 | 40.4 | 62.7 | 62.0 | 50.8 | 46.4 | 45.3 | 46.0 | 39.6 | 41.6 | 33.0 | 20.3 | 20.3 | 22.9 | 22.4 | 25.5 |
| Percentage of Assets chdn:GamingSegment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 2653 | 2584 | 2319 | 2890 | 2893 | 2768 | 2040 | 2012 | 2035 | 2021 | 1251 | 1197 | 1243 | 1257 | 1719 | 1701 | 1680 | 1567 | 1569 | 1529 | 1568 | 1618 | 1660 | 1494 | 1542 | 1603 | 1660 | 617 | 654 | 646 | 647 | 563 | 420 | 443 | 470 | 284 | 313 | 344 | 363 | 371 | 434 | 511 |
| Percentage of Liabilities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 89.3 | 92.7 | 86.3 | 88.6 | 90.0 | 86.4 | 80.0 | 78.5 | 78.6 | 81.6 | 72.6 | 69.9 | 73.3 | 78.5 | 72.9 | 73.1 | 73.7 | 69.5 | 69.6 | 68.7 | 69.8 | 72.3 | 72.9 | 66.1 | 67.1 | 69.7 | 70.3 | 46.3 | 48.0 | 47.8 | 47.9 | 43.8 | 37.2 | 40.4 | 42.2 | 30.3 | 32.7 | 36.7 | 38.4 | 38.8 | 43.5 | 50.3 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 2970 | 2787 | 2686 | 3263 | 3216 | 3203 | 2551 | 2562 | 2588 | 2478 | 1725 | 1711 | 1696 | 1601 | 2359 | 2327 | 2282 | 2256 | 2254 | 2224 | 2248 | 2238 | 2277 | 2260 | 2298 | 2302 | 2360 | 1332 | 1363 | 1351 | 1352 | 1287 | 1129 | 1097 | 1114 | 939 | 959 | 937 | 948 | 956 | 998 | 1017 |
| Percentage of LiabilitiesAndStockholdersEquity | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2019-12-31 |
| Value | 620 | 599 | 645 | 560 |
| Percentage of LiabilitiesAndStockholdersEquity | 20.9 | 21.5 | 24.0 | 22.0 |
| Percentage of Assets | 20.9 | 21.5 | 24.0 | 22.0 |
| Percentage of Assets us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 | 2009-12-31 | 2008-12-31 |
| Value | 367 | 372 | 320 | 433 | 508 | 550 | 553 | 456 | 473 | 514 | 453 | 343 | 640 | 626 | 601 | 688 | 685 | 695 | 679 | 619 | 617 | 766 | 756 | 698 | 700 | 714 | 709 | 704 | 704 | 724 | 708 | 654 | 644 | 654 | 645 | 592 | 584 | 585 | 564 | 506 | 407 | 393 |
| Percentage of StockholdersEquity | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 13.7 | 11.4 | 10.0 | 13.5 | 19.9 | 21.5 | 21.4 | 18.4 | 27.4 | 30.1 | 26.7 | 21.5 | 27.1 | 26.9 | 26.3 | 30.5 | 30.4 | 31.3 | 30.2 | 27.7 | 27.1 | 33.9 | 32.9 | 30.3 | 29.7 | 53.7 | 52.0 | 52.2 | 52.1 | 56.2 | 62.8 | 59.6 | 57.8 | 69.7 | 67.3 | 63.3 | 61.6 | 61.2 | 56.5 | 49.7 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 532 | 346 | 235 | 806 | 817 | 843 | 221 | 301 | 348 | 259 | 241 | 230 | 354 | 294 | 256 | 234 | 208 | 213 | 246 | 201 | 209 | 198 | 222 | 209 | 215 | 202 | 241 | 126 | 153 | 149 | 160 | 147 | 156 | 133 | 147 | 133 | 151 | 124 | 144 | 145 | 177 | 169 |
| Percentage of AssetsCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 17.9 | 12.4 | 8.8 | 24.7 | 25.4 | 26.3 | 8.7 | 11.8 | 13.5 | 10.5 | 14.0 | 13.5 | 20.9 | 18.4 | 10.9 | 10.1 | 9.1 | 9.5 | 10.9 | 9.0 | 9.3 | 8.8 | 9.8 | 9.2 | 9.4 | 8.8 | 10.2 | 9.5 | 11.3 | 11.0 | 11.9 | 11.5 | 13.8 | 12.2 | 13.2 | 14.2 | 15.8 | 13.2 | 15.2 | 15.2 | 17.8 | 16.7 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2019-12-31 |
| Value | 86 | 87 | 132 | 64 |
| Percentage of AssetsCurrent | 16.2 | 25.3 | 56.5 | 28.9 |
| Percentage of Assets | 2.9 | 3.1 | 4.9 | 2.5 |
| Percentage of Assets us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees | 13.9 | 14.6 | 20.6 | 11.4 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2009-12-31 | 2008-12-31 |
| Value | 342 | 147 | 67 | 622 | 649 | 700 | 96 | 189 | 202 | 119 | 133 | 131 | 254 | 202 | 51 | 57 | 41 | 54 | 48 | 56 | 55 | 51 | 74 | 51 | 59 | 49 | 67 | 42 | 46 | 47 | 44 | 43 | 38 | 39 | 37 | 29 | 31 | 28 | 27 | 26 | 31 | 27 | 26 | 14 | 24 | 13 | 12 |
| Percentage of CashAndCashEquivalentsAtCarryingValue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 11.5 | 5.3 | 2.5 | 19.1 | 20.2 | 21.9 | 3.8 | 7.4 | 7.8 | 4.8 | 7.7 | 7.7 | 15.0 | 12.7 | 2.2 | 2.5 | 1.8 | 2.4 | 2.2 | 2.6 | 2.5 | 2.3 | 3.3 | 2.3 | 2.6 | 2.2 | 2.9 | 3.2 | 3.4 | 3.5 | 3.3 | 3.4 | 3.4 | 3.6 | 3.3 | 3.2 | 3.3 | 3.1 | 2.9 | 2.8 | 3.1 | 0.0 | 2.6 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2016-12-31 |
| Value | 411 | 195 | 121 | 679 | 699 | 744 | 142 | 233 | 245 | 157 | 173 | 170 | 294 | 234 | 85 | 83 |
| Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 13.8 | 7.0 | 4.5 | 20.8 | 21.7 | 23.2 | 5.6 | 9.1 | 9.5 | 6.4 | 10.0 | 9.9 | 17.4 | 14.6 | 3.6 | 3.7 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 50 | 45 | 36 | 53 | 47 | 36 | 37 | 35 | 72 | 47 | 28 | 33 | 37 | 34 | 49 | 74 | 70 | 62 | 81 | 50 | 61 | 52 | 67 | 61 | 66 | 60 | 75 | 35 | 45 | 35 | 46 | 40 | 46 | 26 | 47 | 38 | 44 | 24 | 49 | 33 | 41 | 33 |
| Percentage of AccountsReceivableNetCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 1.7 | 1.6 | 1.4 | 1.6 | 1.5 | 1.1 | 1.5 | 1.4 | 2.8 | 1.9 | 1.7 | 2.0 | 2.2 | 2.2 | 2.1 | 3.2 | 3.1 | 2.8 | 3.6 | 2.3 | 2.7 | 2.3 | 3.0 | 2.7 | 2.9 | 2.6 | 3.2 | 2.7 | 3.4 | 2.6 | 3.4 | 3.1 | 4.1 | 2.4 | 4.2 | 4.1 | 4.6 | 2.6 | 5.3 | 3.5 | 4.1 | 3.3 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 31 | 36 | 28 | 33 | 34 | 36 | 26 | 31 | 30 | 37 | 22 | 26 | 22 | 26 | 18 | 59 | 54 | 57 | 50 | 51 | 51 | 53 | 39 | 38 | 33 | 35 | 24 | 16 | 18 | 20 | 12 | 14 | 17 | 22 | 13 | 11 | 14 | 17 | 10 | 18 | 20 | 20 |
| Percentage of OtherAssetsCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 1.1 | 1.3 | 1.0 | 1.0 | 1.1 | 1.1 | 1.1 | 1.2 | 1.2 | 1.5 | 1.3 | 1.5 | 1.3 | 1.6 | 0.8 | 2.5 | 2.4 | 2.6 | 2.3 | 2.3 | 2.3 | 2.4 | 1.7 | 1.7 | 1.4 | 1.5 | 1.0 | 1.2 | 1.3 | 1.5 | 0.9 | 1.1 | 1.5 | 2.0 | 1.2 | 1.3 | 1.5 | 1.9 | 1.1 | 2.0 | 2.0 | 2.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 1781 | 1547 | 1317 | 1122 | 1051 | 1002 | 1006 | 946 | 856 | 747 |
| Percentage of PropertyPlantAndEquipmentGross | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 66.3 | 60.7 | 76.4 | 47.6 | 46.6 | 44.0 | 42.6 | 70.0 | 76.8 | 78.9 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 |
| Value | 785 | 625 | 532 | 439 | 414 | 412 |
| Percentage of PropertyPlantAndEquipmentGross | 44.1 | 40.4 | 40.4 | 39.2 | 39.4 | 41.1 |
| Percentage of Assets | 29.2 | 24.5 | 30.9 | 18.6 | 18.4 | 18.1 |
| Percentage of Assets chdn:GrandstandandBuildings | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 240 | 222 | 207 | 177 | 157 | 142 | 142 | 121 | 92 | 80 |
| Percentage of PropertyPlantAndEquipmentGross | 13.5 | 14.4 | 15.7 | 15.9 | 15.0 | 14.2 | 14.2 | 12.8 | 10.8 | 10.8 |
| Percentage of Assets | 9.0 | 8.7 | 12.0 | 7.5 | 7.0 | 6.3 | 6.1 | 9.0 | 8.3 | 8.5 |
| Percentage of Assets chdn:TracksAndOtherImprovements | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 23 | 52 | 7.0 | 23 | 27 | 22 | 15 | 15 | 7.793 | 4.548 |
| Percentage of PropertyPlantAndEquipmentGross | 1.3 | 3.4 | 0.5 | 2.1 | 2.6 | 2.3 | 1.5 | 1.6 | 0.9 | 0.6 |
| Percentage of Assets | 0.9 | 2.1 | 0.4 | 1.0 | 1.2 | 1.0 | 0.7 | 1.1 | 0.7 | 0.5 |
| Percentage of Assets us-gaap:ConstructionInProgress | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 477 | 406 | 356 | 286 | 275 | 252 | 237 | 208 | 180 | 155 |
| Percentage of PropertyPlantAndEquipmentGross | 26.8 | 26.3 | 27.0 | 25.6 | 26.2 | 25.1 | 23.6 | 22.1 | 21.1 | 20.8 |
| Percentage of Assets | 17.8 | 15.9 | 20.7 | 12.2 | 12.2 | 11.1 | 10.1 | 15.5 | 16.2 | 16.4 |
| Percentage of Assets us-gaap:Equipment | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 89 | 79 | 73 | 60 | 57 | 52 | 51 | 47 | 45 | 38 |
| Percentage of PropertyPlantAndEquipmentGross | 5.0 | 5.1 | 5.6 | 5.4 | 5.5 | 5.2 | 5.1 | 5.0 | 5.4 | 5.1 |
| Percentage of Assets | 3.3 | 3.1 | 4.2 | 2.6 | 2.5 | 2.3 | 2.2 | 3.5 | 4.1 | 4.0 |
| Percentage of Assets us-gaap:FurnitureAndFixtures | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 164 | 162 | 140 | 131 | 117 | 118 | 118 | 118 | 115 | 104 |
| Percentage of PropertyPlantAndEquipmentGross | 9.2 | 10.5 | 10.7 | 11.7 | 11.2 | 11.8 | 11.8 | 12.5 | 13.5 | 13.9 |
| Percentage of Assets | 6.1 | 6.4 | 8.1 | 5.6 | 5.2 | 5.2 | 5.0 | 8.7 | 10.4 | 11.0 |
| Percentage of Assets us-gaap:Land | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 721 | 635 | 559 | 514 | 477 | 429 | 411 | 360 | 313 | 270 |
| Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 26.9 | 24.9 | 32.4 | 21.8 | 21.2 | 18.9 | 17.4 | 26.7 | 28.1 | 28.5 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 1057 | 1068 | 1059 | 1081 | 1043 | 990 | 912 | 895 | 880 | 866 | 757 | 753 | 668 | 634 | 608 | 619 | 602 | 590 | 574 | 573 | 577 | 573 | 573 | 571 | 589 | 590 | 595 | 591 | 595 | 590 | 585 | 576 | 537 | 539 | 542 | 469 | 471 | 475 | 477 | 482 | 486 | 507 |
| Percentage of PropertyPlantAndEquipmentNet | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 35.6 | 38.3 | 39.5 | 33.2 | 32.4 | 30.9 | 35.8 | 34.9 | 34.0 | 35.0 | 43.9 | 44.0 | 39.4 | 39.7 | 25.8 | 26.6 | 26.4 | 26.2 | 25.5 | 25.8 | 25.7 | 25.6 | 25.2 | 25.3 | 25.6 | 25.6 | 25.2 | 44.4 | 43.7 | 43.7 | 43.3 | 44.7 | 47.6 | 49.1 | 48.7 | 50.0 | 49.2 | 50.7 | 50.4 | 50.4 | 48.8 | 49.9 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2019-12-31 |
| Value | 268 | 265 | 267 | 256 |
| Percentage of PropertyPlantAndEquipmentNet | 25.3 | 24.9 | 25.2 | 28.1 |
| Percentage of Assets | 9.0 | 9.5 | 10.0 | 10.0 |
| Percentage of Assets us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees | 43.2 | 44.3 | 41.5 | 45.7 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2012-12-31 |
| Value | 644 | 633 | 630 | 634 | 615 | 630 | 634 | 625 | 621 | 625 | 108 | 107 | 176 | 173 | 171 | 173 | 168 | 164 | 139 | 131 | 130 | 129 | 129 | 106 | 107 | 108 | 109 | 99 | 97 | 94 | 86 | 19 |
| Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 21.7 | 22.7 | 23.5 | 19.4 | 19.1 | 19.7 | 24.9 | 24.4 | 24.0 | 25.2 | 6.3 | 6.3 | 10.4 | 10.8 | 7.3 | 7.5 | 7.4 | 7.3 | 6.2 | 5.9 | 5.8 | 5.8 | 5.7 | 4.7 | 4.7 | 4.7 | 4.6 | 7.4 | 7.2 | 7.0 | 6.4 | 1.7 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 366 | 366 | 366 | 366 | 366 | 367 | 367 | 363 | 363 | 363 | 338 | 337 | 317 | 317 | 317 | 848 | 847 | 832 | 832 | 841 | 841 | 841 | 841 | 841 | 840 | 840 | 839 | 300 | 300 | 300 | 300 | 298 | 250 | 250 | 250 | 217 | 217 | 216 | 213 | 213 | 213 | 214 |
| Percentage of Goodwill | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 12.3 | 13.2 | 13.7 | 11.2 | 11.4 | 11.5 | 14.4 | 14.2 | 14.1 | 14.7 | 19.6 | 19.7 | 18.7 | 19.8 | 13.5 | 36.4 | 37.1 | 36.9 | 36.9 | 37.8 | 37.4 | 37.6 | 37.0 | 37.2 | 36.6 | 36.5 | 35.6 | 22.6 | 22.1 | 22.3 | 22.2 | 23.2 | 22.2 | 22.8 | 22.5 | 23.2 | 22.7 | 23.1 | 22.5 | 22.3 | 21.4 | 21.1 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 |
| Value | 3.7 | 4.0 | 1.0 |
| Percentage of Goodwill | 1.0 | 1.1 | 0.3 |
| Percentage of Assets | 0.1 | 0.2 | 0.1 |
| Percentage of Assets us-gaap:CorporateNonSegment | 0.3 | 0.4 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 |
| Value | 165 | 165 | 139 |
| Percentage of Goodwill | 45.0 | 45.0 | 41.2 |
| Percentage of Assets | 6.1 | 6.5 | 8.1 |
| Percentage of Assets us-gaap:OperatingSegments chdn:GamingSegment | 17.4 | 16.0 | 0.0 |
| Period End | 2021-03-31 |
| Value | -4.0 |
| Percentage of Goodwill | -1.1 |
| Percentage of Assets | -0.1 |
| Percentage of Assets srt:RestatementAdjustment chdn:GamingSegment | 0.0 |
| Period End | 2021-03-31 |
| Value | 4.0 |
| Percentage of Goodwill | 1.1 |
| Percentage of Assets | 0.1 |
| Percentage of Assets srt:RestatementAdjustment chdn:TwinSpires | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2017-12-31 | 2013-12-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 | 2010-12-31 |
| Value | 165 | 165 | 165 | 165 | 164 | 164 | 164 | 139 | 118 | 117 | 67 | 34 | 34 | 34 | 35 |
| Percentage of Goodwill | 45.0 | 45.0 | 45.0 | 45.0 | 45.3 | 45.3 | 45.3 | 41.2 | 37.4 | 39.1 | 26.9 | 15.9 | 15.9 | 16.2 | 16.4 |
| Percentage of Assets | 5.1 | 5.1 | 5.2 | 6.5 | 6.4 | 6.4 | 6.7 | 8.1 | 5.0 | 8.7 | 6.1 | 3.7 | 3.6 | 3.7 | 3.4 |
| Percentage of Assets chdn:GamingSegment | 0.0 | 0.0 | 0.0 | 16.0 | 10.3 | 10.3 | 0.0 | 15.9 | 0.0 | 22.0 | 29.9 | 16.1 | 16.1 | 14.3 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 |
| Value | 3.7 | 3.7 | 4.0 | 4.0 | 1.0 | 1.0 |
| Percentage of Goodwill | 1.0 | 1.0 | 1.1 | 1.1 | 0.3 | 0.3 |
| Percentage of Assets | 0.1 | 0.1 | 0.1 | 0.2 | 0.1 | 0.0 |
| Percentage of Assets us-gaap:AllOtherSegments | 0.0 | 0.0 | 0.0 | 0.0 | 1.3 | 6.6 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 |
| Value | 336 | 336 | 350 | 336 | 336 | 336 | 369 | 338 | 338 | 328 | 264 | 245 | 150 | 150 | 169 | 358 | 358 | 358 | 445 | 358 | 358 | 358 | 496 | 358 | 358 | 358 | 549 | 158 | 158 | 158 | 198 | 163 | 97 | 97 | 143 | 64 | 64 | 59 |
| Percentage of IndefiniteLivedIntangibleAssetsExcludingGoodwill | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 11.3 | 12.1 | 13.1 | 10.3 | 10.4 | 10.5 | 14.5 | 13.2 | 13.1 | 13.2 | 15.3 | 14.3 | 8.9 | 9.4 | 7.2 | 15.4 | 15.7 | 15.9 | 19.8 | 16.1 | 15.9 | 16.0 | 21.8 | 15.9 | 15.6 | 15.6 | 23.3 | 11.9 | 11.6 | 11.7 | 14.7 | 12.7 | 8.6 | 8.9 | 12.8 | 6.9 | 6.7 | 6.3 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 288 | 303 | 216 | 128 | 128 | 128 | 128 | 128 | 70 | 45 |
| Percentage of IndefiniteLivedIntangibleAssetsExcludingGoodwill | 82.2 | 82.0 | 82.0 | 76.1 | 28.9 | 26.0 | 23.4 | 65.0 | 49.2 | 75.3 |
| Percentage of Assets | 10.7 | 11.9 | 12.5 | 5.5 | 5.7 | 5.7 | 5.5 | 9.5 | 6.3 | 4.8 |
| Percentage of Assets us-gaap:ContractualRights | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 0.1 | 0.1 | 0.1 | 0.1 | 0.4 | 0.417 | 0.417 | 0.417 | 0.417 | 0.217 |
| Percentage of IndefiniteLivedIntangibleAssetsExcludingGoodwill | 0.0 | 0.0 | 0.0 | 0.1 | 0.1 | 0.1 | 0.1 | 0.2 | 0.3 | 0.4 |
| Percentage of Assets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Assets us-gaap:OtherIntangibleAssets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 47 | 50 | 29 | 21 | 225 | 225 | 225 | 25 | 23 | 11 |
| Percentage of IndefiniteLivedIntangibleAssetsExcludingGoodwill | 13.6 | 13.6 | 11.2 | 12.5 | 50.6 | 45.5 | 41.0 | 13.0 | 16.3 | 18.9 |
| Percentage of Assets | 1.8 | 2.0 | 1.7 | 0.9 | 10.0 | 9.9 | 9.6 | 1.9 | 2.1 | 1.2 |
| Percentage of Assets us-gaap:Trademarks | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 348 | 349 | 350 | 351 | 350 | 351 | 369 | 355 | 354 | 345 | 264 | 264 | 166 | 167 | 169 | 425 | 434 | 435 | 445 | 458 | 471 | 482 | 496 | 509 | 521 | 535 | 549 | 191 | 192 | 195 | 198 | 205 | 139 | 140 | 143 | 102 | 103 | 106 | 103 | 106 | 109 | 113 |
| Percentage of IntangibleAssetsNetExcludingGoodwill | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 11.7 | 12.5 | 13.1 | 10.8 | 10.9 | 11.0 | 14.5 | 13.9 | 13.7 | 13.9 | 15.3 | 15.5 | 9.8 | 10.5 | 7.2 | 18.3 | 19.0 | 19.3 | 19.8 | 20.6 | 21.0 | 21.6 | 21.8 | 22.6 | 22.7 | 23.3 | 23.3 | 14.4 | 14.1 | 14.5 | 14.7 | 16.0 | 12.3 | 12.8 | 12.8 | 11.0 | 10.8 | 11.4 | 11.0 | 11.2 | 11.0 | 11.1 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 |
| Value | 12 | 13 | 14 | 15 | 14 | 15 | 16 | 17 | 16 | 16 | 18 | 19 | 16 | 17 | 19 | 67 | 75 | 77 | 87 | 100 | 113 | 124 | 137 | 151 | 163 | 177 | 191 | 33 | 34 | 36 | 39 | 42 | 41 | 42 | 45 | 38 | 38 | 43 |
| Percentage of FiniteLivedIntangibleAssetsNet | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 0.4 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.6 | 0.7 | 0.6 | 0.7 | 1.0 | 1.1 | 1.0 | 1.1 | 0.8 | 2.9 | 3.3 | 3.4 | 3.9 | 4.5 | 5.0 | 5.6 | 6.1 | 6.7 | 7.1 | 7.7 | 8.1 | 2.5 | 2.5 | 2.7 | 2.9 | 3.3 | 3.7 | 3.9 | 4.1 | 4.1 | 4.0 | 4.6 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 2.2 | 2.9 | 3.5 | 4.2 | 4.8 | 5.446 | 6.093 | 6.74 | 7.387 | 8.034 |
| Percentage of FiniteLivedIntangibleAssetsNet | 15.1 | 17.8 | 19.4 | 21.9 | 5.5 | 4.0 | 3.2 | 16.9 | 16.2 | 18.3 |
| Percentage of Assets | 0.1 | 0.1 | 0.2 | 0.2 | 0.2 | 0.2 | 0.3 | 0.5 | 0.7 | 0.8 |
| Percentage of Assets chdn:FavorableContracts | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 2.5 | 3.1 | 3.9 | 6.1 | 9.7 | 27 | 49 | 26 | 33 | 30 |
| Percentage of FiniteLivedIntangibleAssetsNet | 17.1 | 19.0 | 21.7 | 31.8 | 11.1 | 20.3 | 26.0 | 65.5 | 73.0 | 70.4 |
| Percentage of Assets | 0.1 | 0.1 | 0.2 | 0.3 | 0.4 | 1.2 | 2.1 | 1.9 | 3.0 | 3.3 |
| Percentage of Assets us-gaap:CustomerRelationships | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 |
| Value | 3.0 | 3.1 | 3.4 | 3.3 |
| Percentage of FiniteLivedIntangibleAssetsNet | 20.5 | 19.0 | 18.9 | 17.2 |
| Percentage of Assets | 0.1 | 0.1 | 0.2 | 0.1 |
| Percentage of Assets us-gaap:License | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 6.9 | 7.2 | 7.2 | 5.6 | 2.7 | 3.343 | 3.393 | 3.422 | 3.812 | 3.822 |
| Percentage of FiniteLivedIntangibleAssetsNet | 47.3 | 44.2 | 40.0 | 29.2 | 3.1 | 2.4 | 1.8 | 8.6 | 8.4 | 8.7 |
| Percentage of Assets | 0.3 | 0.3 | 0.4 | 0.2 | 0.1 | 0.1 | 0.1 | 0.3 | 0.3 | 0.4 |
| Percentage of Assets us-gaap:OtherIntangibleAssets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 22 | 24 |
| Percentage of OperatingLeaseRightOfUseAsset | 100.0 | 100.0 |
| Percentage of Assets | 0.8 | 1.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 20 | 21 | 21 | 22 | 22 | 21 | 21 | 20 | 19 | 18 | 16 | 17 | 13 | 12 | 13 | 12 | 12 | 11 | 10 | 13 | 13 | 12 | 13 | 22 | 24 | 24 | 24 | 22 | 22 | 20 | 21 | 60 | 45 | 33 | 30 | 15 | 14 | 13 | 8.665 | 8.787 | 10 | 12 |
| Percentage of OtherAssetsNoncurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 0.7 | 0.8 | 0.8 | 0.7 | 0.7 | 0.7 | 0.8 | 0.8 | 0.8 | 0.7 | 0.9 | 1.0 | 0.8 | 0.8 | 0.6 | 0.5 | 0.5 | 0.5 | 0.5 | 0.6 | 0.6 | 0.6 | 0.6 | 1.0 | 1.1 | 1.1 | 1.0 | 1.7 | 1.7 | 1.5 | 1.6 | 4.7 | 4.1 | 3.1 | 2.8 | 1.7 | 1.6 | 1.5 | 0.9 | 0.9 | 1.0 | 1.2 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2019-12-31 |
| Value | 266 | 246 | 244 | 240 |
| Percentage of OtherAssetsNoncurrent | 1280.3 | 1135.9 | 1155.2 | 1137.9 |
| Percentage of Assets | 9.0 | 8.8 | 9.1 | 9.4 |
| Percentage of Assets us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees | 42.9 | 41.1 | 38.0 | 42.9 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 124 | 74 | 70 | 108 | 105 | 80 | 57 | 75 | 107 | 72 | 47 | 60 | 79 | 59 | 54 | 61 | 87 | 56 | 53 | 53 | 74 | 57 | 39 | 52 | 66 | 51 | 45 | 49 | 70 | 51 | 43 | 71 | 81 | 63 | 62 | 59 | 68 | 53 | 56 | 42 | 56 | 47 |
| Percentage of AccountsPayableCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 4.2 | 2.7 | 2.6 | 3.3 | 3.3 | 2.5 | 2.3 | 3.0 | 4.1 | 2.9 | 2.7 | 3.5 | 4.7 | 3.7 | 2.3 | 2.6 | 3.8 | 2.5 | 2.4 | 2.4 | 3.3 | 2.6 | 1.7 | 2.3 | 2.9 | 2.3 | 1.9 | 3.7 | 5.2 | 3.8 | 3.2 | 5.6 | 7.2 | 5.8 | 5.6 | 6.3 | 7.2 | 5.7 | 6.0 | 4.4 | 5.6 | 4.7 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 |
| Value | 32 | 42 | 47 |
| Percentage of ContractWithCustomerLiabilityCurrent | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 1.2 | 1.7 | 2.8 |
| Period End | 2020-12-31 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 24 | 0.0 | 0.0 | 23 | 0.0 | 0.0 | 0.0 | 22 | 0.0 | 0.0 | 0.0 | 23 | 0.0 | 0.0 | 0.0 | 21 | 0.0 | 0.0 | 0.0 | 19 | 0.0 | 0.0 | 0.0 | 17 | 0.0 | 0.0 | 0.0 | 15 | 0.0 | 0.0 | 0.0 | 0.0 | 10 | 0.0 | 0.0 | 8.165 |
| Percentage of DividendsPayableCurrent | 100.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 100.0 |
| Percentage of Assets | 0.9 | 0.0 | 0.0 | 0.9 | 0.0 | 0.0 | 0.0 | 1.3 | 0.0 | 0.0 | 0.0 | 1.0 | 0.0 | 0.0 | 0.0 | 1.0 | 0.0 | 0.0 | 0.0 | 0.8 | 0.0 | 0.0 | 0.0 | 0.7 | 0.0 | 0.0 | 0.0 | 1.1 | 0.0 | 0.0 | 0.0 | 0.0 | 1.1 | 0.0 | 0.0 | 0.8 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 369 | 305 | 424 | 471 | 488 | 344 | 301 | 275 | 308 | 297 | 256 | 210 | 274 | 289 | 453 | 412 | 441 | 421 | 468 | 391 | 431 | 420 | 640 | 613 | 634 | 341 | 334 | 167 | 220 | 214 | 213 | 179 | 203 | 378 | 406 | 158 | 185 | 171 | 173 | 158 | 208 | 188 |
| Percentage of LiabilitiesCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 12.4 | 11.0 | 15.8 | 14.4 | 15.2 | 10.7 | 11.8 | 10.8 | 11.9 | 12.0 | 14.9 | 12.3 | 16.2 | 18.1 | 19.2 | 17.7 | 19.3 | 18.7 | 20.8 | 17.6 | 19.2 | 18.8 | 28.1 | 27.1 | 27.6 | 14.8 | 14.2 | 12.6 | 16.2 | 15.9 | 15.8 | 13.9 | 18.0 | 34.5 | 36.5 | 16.9 | 19.4 | 18.3 | 18.3 | 16.6 | 20.9 | 18.5 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2019-12-31 |
| Value | 78 | 122 | 133 | 73 |
| Percentage of LiabilitiesCurrent | 21.1 | 40.0 | 31.5 | 24.3 |
| Percentage of Assets | 2.6 | 4.4 | 5.0 | 2.9 |
| Percentage of Assets us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees | 12.6 | 20.4 | 20.7 | 13.1 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2011-12-31 |
| Value | 7.0 | 7.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 17 | 16 | 15 | 14 | 13 | 11 | 10 | 16 | 15 | 13 | 12 | 11 | 0.0 | 0.0 | 0.0 | 187 | 209 | 0.0 |
| Percentage of LongTermDebtCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 100.0 | 0.0 |
| Percentage of Assets | 0.2 | 0.3 | 0.1 | 0.1 | 0.1 | 0.1 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.8 | 0.7 | 0.7 | 0.6 | 0.6 | 0.5 | 0.5 | 0.7 | 0.7 | 0.6 | 0.5 | 0.5 | 0.0 | 0.0 | 0.0 | 17.1 | 18.8 | 0.0 |
| Period End | 2020-12-31 |
| Value | 4700000.0 |
| Percentage of OperatingLeaseLiabilityCurrent | 100.0 |
| Percentage of Assets | 0.2 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 1622 | 1473 | 884 | 1129 | 921 | 781 | 759 | 369 | 209 | 127 |
| Percentage of LongTermDebt | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 60.4 | 57.8 | 51.3 | 47.9 | 40.9 | 34.3 | 32.2 | 27.3 | 18.8 | 13.5 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 384 | 388 |
| Percentage of LongTermDebt | 23.7 | 26.3 |
| Percentage of Assets | 14.3 | 15.2 |
| Percentage of Assets us-gaap:SecuredDebt chdn:TermLoanBdue2024 us-gaap:CarryingReportedAmountFairValueDisclosure us-gaap:LineOfCredit | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 |
| Value | 384 | 388 | 391 | 394 |
| Percentage of LongTermDebt | 23.7 | 26.3 | 44.2 | 35.0 |
| Percentage of Assets | 14.3 | 15.2 | 22.7 | 16.7 |
| Percentage of Assets us-gaap:SecuredDebt chdn:A2017CreditAgreement us-gaap:LineOfCredit | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 |
| Value | 149 |
| Percentage of LongTermDebt | 9.2 |
| Percentage of Assets | 5.6 |
| Percentage of Assets chdn:Revolver us-gaap:CarryingReportedAmountFairValueDisclosure us-gaap:LineOfCredit | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 593 | 592 |
| Percentage of LongTermDebt | 36.6 | 40.2 |
| Percentage of Assets | 22.1 | 23.2 |
| Percentage of Assets chdn:SeniorNotesDue2027 us-gaap:CarryingReportedAmountFairValueDisclosure us-gaap:SeniorNotes | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 494 | 493 |
| Percentage of LongTermDebt | 30.5 | 33.5 |
| Percentage of Assets | 18.4 | 19.4 |
| Percentage of Assets chdn:SeniorNotesDue2028 us-gaap:CarryingReportedAmountFairValueDisclosure us-gaap:SeniorNotes | 0.0 | 0.0 |
| Period End | 2020-12-31 |
| Value | 149 |
| Percentage of LongTermDebt | 9.2 |
| Percentage of Assets | 5.6 |
| Percentage of Assets chdn:Revolver us-gaap:LineOfCredit | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 593 | 592 |
| Percentage of LongTermDebt | 36.6 | 40.2 |
| Percentage of Assets | 22.1 | 23.2 |
| Percentage of Assets chdn:SeniorNotesDue2027 us-gaap:SeniorNotes | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 |
| Value | 494 | 493 | 493 | 492 |
| Percentage of LongTermDebt | 30.5 | 33.5 | 55.8 | 43.6 |
| Percentage of Assets | 18.4 | 19.4 | 28.6 | 20.9 |
| Percentage of Assets chdn:SeniorNotesDue2028 us-gaap:SeniorNotes | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2019-12-31 |
| Value | 772 | 722 | 753 | 745 |
| Percentage of LongTermDebt | 0.0 | 0.0 | 46.4 | 50.5 |
| Percentage of Assets | 26.0 | 25.9 | 28.0 | 29.2 |
| Percentage of Assets us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees | 124.4 | 120.4 | 116.8 | 133.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 1618 | 1469 | 384 | 385 | 386 | 880 | 388 | 389 | 390 | 1125 | 510 | 459 | 358 | 907 | 312 | 319 | 382 | 765 | 272 | 299 | 387 | 459 | 383 | 368 | 365 | 369 | 324 | 153 | 0.0 | 69 | 62 | 107 | 127 | 156 | 184 | 265 |
| Percentage of LongTermDebtNoncurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 60.2 | 57.6 | 15.0 | 14.9 | 15.6 | 51.0 | 22.7 | 22.9 | 24.4 | 47.7 | 21.9 | 20.2 | 15.9 | 40.3 | 14.1 | 14.2 | 17.1 | 33.6 | 12.0 | 13.0 | 16.8 | 19.5 | 28.8 | 27.1 | 27.1 | 27.3 | 25.2 | 13.6 | 0.0 | 7.5 | 6.6 | 11.5 | 13.5 | 16.3 | 18.5 | 26.1 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 |
| Value | 12 | 14 | 7.0 | 7.7 | 7.8 | 9.3 |
| Percentage of DeferredFinanceCostsNoncurrentNet | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 0.5 | 0.6 | 0.4 | 0.3 | 0.3 | 0.4 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-01-01 | 2017-12-31 | 2016-12-31 |
| Value | 250 | 248 | 213 | 205 | 188 | 210 | 212 | 209 | 199 | 194 | 78 | 40 | 40 | 63 |
| Percentage of DeferredIncomeTaxLiabilitiesNet | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 8.4 | 8.9 | 8.0 | 6.3 | 5.8 | 6.6 | 8.3 | 8.2 | 7.7 | 7.8 | 4.5 | 0.0 | 1.7 | 2.8 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 55 | 48 | 45 | 36 | 38 | 38 | 39 | 38 | 38 | 38 | 15 | 17 | 17 | 16 | 16 | 19 | 18 | 17 | 16 | 15 | 15 | 18 | 18 | 23 | 24 | 23 | 21 | 20 | 19 | 18 | 17 | 18 | 23 | 21 | 21 | 22 | 31 | 30 | 29 | 30 | 16 | 17 |
| Percentage of OtherLiabilitiesNoncurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 1.9 | 1.7 | 1.7 | 1.1 | 1.2 | 1.2 | 1.5 | 1.5 | 1.5 | 1.5 | 0.9 | 1.0 | 1.1 | 1.0 | 0.7 | 0.8 | 0.8 | 0.8 | 0.7 | 0.7 | 0.7 | 0.8 | 0.8 | 1.1 | 1.1 | 1.0 | 0.9 | 1.5 | 1.4 | 1.4 | 1.3 | 1.4 | 2.1 | 2.0 | 1.9 | 2.4 | 3.3 | 3.3 | 3.1 | 3.2 | 1.6 | 1.7 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2019-12-31 |
| Value | 32 | 35 | 42 | 20 |
| Percentage of OtherLiabilitiesNoncurrent | 58.7 | 73.9 | 92.4 | 52.3 |
| Percentage of Assets | 1.1 | 1.3 | 1.6 | 0.8 |
| Percentage of Assets us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees | 5.3 | 5.9 | 6.6 | 3.7 |
| Period End | 2020-12-31 |
| Value | 19 |
| Percentage of OperatingLeaseLiabilityNoncurrent | 100.0 |
| Percentage of Assets | 0.7 |
| Period End | 2020-12-31 |
| Value | 4300000.0 |
| Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo | 100.0 |
| Percentage of Assets | 0.2 |
| Period End | 2020-12-31 |
| Value | 3800000.0 |
| Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearThree | 100.0 |
| Percentage of Assets | 0.1 |
| Period End | 2020-12-31 |
| Value | 3800000.0 |
| Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour | 100.0 |
| Percentage of Assets | 0.1 |
| Period End | 2020-12-31 |
| Value | 3600000.0 |
| Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFive | 100.0 |
| Percentage of Assets | 0.1 |
| Period End | 2020-12-31 |
| Value | 5500000.0 |
| Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive | 100.0 |
| Percentage of Assets | 0.2 |
| Period End | 2020-12-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 23 | 26 | 27 | 26 | 26 |
| Percentage of OperatingLeaseLiability | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 0.9 | 1.0 | 1.1 | 1.0 | 1.1 |
| Period End | 2020-12-31 |
| Value | 26 |
| Percentage of LesseeOperatingLeaseLiabilityPaymentsDue | 100.0 |
| Percentage of Assets | 1.0 |
| Period End | 2020-12-31 |
| Value | 2800000.0 |
| Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount | 100.0 |
| Percentage of Assets | 0.1 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 | 2009-12-31 | 2008-12-31 |
| Value | 367 | 372 | 320 | 433 | 508 | 550 | 553 | 456 | 473 | 514 | 453 | 343 | 640 | 626 | 601 | 688 | 685 | 695 | 679 | 619 | 617 | 766 | 756 | 698 | 700 | 714 | 709 | 704 | 704 | 724 | 708 | 654 | 644 | 654 | 645 | 592 | 584 | 585 | 564 | 506 | 407 | 393 |
| Percentage of StockholdersEquity | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 13.7 | 11.4 | 10.0 | 13.5 | 19.9 | 21.5 | 21.4 | 18.4 | 27.4 | 30.1 | 26.7 | 21.5 | 27.1 | 26.9 | 26.3 | 30.5 | 30.4 | 31.3 | 30.2 | 27.7 | 27.1 | 33.9 | 32.9 | 30.3 | 29.7 | 53.7 | 52.0 | 52.2 | 52.1 | 56.2 | 62.8 | 59.6 | 57.8 | 69.7 | 67.3 | 63.3 | 61.6 | 61.2 | 56.5 | 49.7 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 |
| Value | 317 | 202 | 367 | 372 | 322 | 435 | 511 | 550 | 553 | 456 | 473 | 640 | 685 |
| Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 10.7 | 7.3 | 13.7 | 11.4 | 10.0 | 13.6 | 20.0 | 21.5 | 21.4 | 18.4 | 27.4 | 27.1 | 30.4 |
| Period End | 2020-12-31 | 2020-03-31 | 2019-12-31 | 2018-12-31 |
| Value | -0.5 | -0.5 | -0.3 | 29 |
| Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest | -0.1 | -0.1 | -0.1 | 6.3 |
| Percentage of Assets | -0.0 | -0.0 | -0.0 | 1.7 |
| Percentage of Assets srt:CumulativeEffectPeriodOfAdoptionAdjustment | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-03-31 | 2019-12-31 | 2018-12-31 |
| Value | -0.5 | -0.5 | -0.3 | 29 |
| Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest | -0.1 | -0.1 | -0.1 | 6.3 |
| Percentage of Assets | -0.0 | -0.0 | -0.0 | 1.7 |
| Percentage of Assets srt:CumulativeEffectPeriodOfAdoptionAdjustment us-gaap:RetainedEarnings | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 |
| Value | -0.9 | -0.9 | -0.9 | -0.9 | -0.9 | -0.9 | -0.9 | -0.9 | -0.9 | -0.9 | -0.9 | -1.3 | -1.2 |
| Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest | -0.3 | -0.4 | -0.2 | -0.2 | -0.3 | -0.2 | -0.2 | -0.2 | -0.2 | -0.2 | -0.2 | -0.2 | -0.2 |
| Percentage of Assets | -0.0 | -0.0 | -0.0 | -0.0 | -0.0 | -0.0 | -0.0 | -0.0 | -0.0 | -0.0 | -0.1 | -0.1 | -0.1 |
| Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 |
| Value | 8.8 | 1.7 | 18 | 15 | 6.1 | 0.0 | 0.0 | 2.9 | 0.0 | 0.0 | 7.3 | 116 |
| Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest | 2.8 | 0.8 | 5.0 | 4.2 | 1.9 | 0.0 | 0.0 | 0.5 | 0.0 | 0.0 | 1.1 | 17.0 |
| Percentage of Assets | 0.3 | 0.1 | 0.7 | 0.5 | 0.2 | 0.0 | 0.0 | 0.1 | 0.0 | 0.0 | 0.3 | 5.2 |
| Percentage of Assets us-gaap:CommonStock | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 |
| Value | 309 | 201 | 349 | 357 | 314 | 433 | 509 | 551 | 551 | 457 | 474 | 634 | 569 |
| Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest | 97.5 | 99.6 | 95.3 | 96.1 | 97.6 | 99.6 | 99.6 | 100.2 | 99.6 | 100.2 | 100.2 | 99.1 | 83.2 |
| Percentage of Assets | 10.4 | 7.2 | 13.0 | 11.0 | 9.8 | 13.5 | 20.0 | 21.5 | 21.3 | 18.5 | 27.5 | 26.9 | 25.3 |
| Percentage of Assets us-gaap:RetainedEarnings | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 8.8 | 1.7 | 18 | 15 | 6.1 | 0.0 | 0.0 | 0.0 | 2.9 | 0.0 | 0.0 | 11 | 6.0 | 0.0 | 7.3 | 0.0 | 0.0 | 113 | 116 | 130 | 123 | 133 | 134 | 271 | 265 | 262 | 262 | 246 | 243 | 296 | 295 | 294 | 287 | 283 | 274 | 274 | 271 | 267 | 260 | 259 | 257 | 236 |
| Percentage of CommonStockValue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 0.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 0.3 | 0.1 | 0.7 | 0.5 | 0.2 | 0.0 | 0.0 | 0.0 | 0.1 | 0.0 | 0.0 | 0.7 | 0.4 | 0.0 | 0.3 | 0.0 | 0.0 | 5.0 | 5.2 | 5.9 | 5.5 | 6.0 | 5.9 | 12.0 | 11.6 | 11.4 | 11.1 | 18.5 | 17.9 | 21.9 | 21.9 | 22.8 | 25.5 | 25.8 | 24.7 | 29.2 | 28.3 | 28.6 | 27.4 | 27.1 | 25.8 | 23.2 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 309 | 201 | 349 | 357 | 314 | 433 | 509 | 551 | 551 | 457 | 474 | 504 | 448 | 344 | 634 | 627 | 602 | 577 | 569 | 565 | 556 | 486 | 483 | 495 | 491 | 436 | 437 | 468 | 465 | 408 | 408 | 430 | 420 | 370 | 369 | 379 | 373 | 325 | 323 | 326 | 306 | 269 |
| Percentage of RetainedEarningsAccumulatedDeficit | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 10.4 | 7.2 | 13.0 | 11.0 | 9.8 | 13.5 | 20.0 | 21.5 | 21.3 | 18.5 | 27.5 | 29.5 | 26.4 | 21.5 | 26.9 | 27.0 | 26.4 | 25.6 | 25.3 | 25.4 | 24.7 | 21.7 | 21.2 | 21.9 | 21.4 | 18.9 | 18.6 | 35.2 | 34.1 | 30.2 | 30.2 | 33.4 | 37.3 | 33.8 | 33.2 | 40.4 | 39.0 | 34.7 | 34.2 | 34.1 | 30.7 | 26.5 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2019-12-31 |
| Value | -262.0 | -279.8 | -284.1 | -278.7 |
| Percentage of RetainedEarningsAccumulatedDeficit | -84.7 | -138.9 | -81.2 | -54.7 |
| Percentage of Assets | -8.8 | -10.0 | -10.6 | -10.9 |
| Percentage of Assets us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees | -42.2 | -46.6 | -44.0 | -49.8 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 6.9 | 6.1 | 4.3 | 5.5 | 7.4 | 4.7 | 3.9 | 6.4 | 6.2 |
| Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 230 | -19.8 | 4.6 | 60 | 33 | 43 | 29 | 45 | 144 | 70 | 62 | -26.9 | 106 | 55 | 54 | -6.9 | 96 | 74 | 37 | 22 | 100 | 66 | 41 | 29 | 104 | 89 | 27 | -4.843 | 67 | 51 | 30 | 14 | 53 | 46 | 42 | 6.059 | 40 | 55 | 41 | 26 | 44 | 60 | 4.516 | -2.545 |
| Percentage of NetCashProvidedByUsedInOperatingActivities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 44.7 | -6.1 | 1.7 | 17.9 | 18.0 | 17.2 | 10.5 | 15.0 | 30.2 | 26.5 | 28.5 | -12.2 | 0.0 | 0.0 | 30.2 | 0.0 | 0.0 | 0.0 | 13.6 | 0.0 | 0.0 | 0.0 | 15.2 | 0.0 | 0.0 | 0.0 | 16.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 15.1 | 39.9 | -7.6 | 16.1 | 17.8 | 46.0 | 3.3 | -1.7 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | -18.2 | -12.3 | -26.6 | -81.0 | -83.5 | -48.3 | -90.6 | -36.7 | -34.8 | -619.1 | -24.8 | -43.5 | -44.3 | 936 | -29.0 | -27.3 | -45.9 | -51.4 | -4.5 | -10.6 | -20.6 | -15.0 | -37.131 | -10.382 | -12.888 | -5.084 | -380.885 | -12.211 | -19.335 | -27.877 | -60.93 | -178.418 | -22.721 | -19.803 | -164.074 | -7.92 | -5.146 | -22.848 | -7.784 | -5.333 | -8.861 | -5.083 | -142.869 | -6.656 |
| Percentage of NetCashProvidedByUsedInInvestingActivities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | -3.5 | -3.8 | -9.6 | -24.0 | -45.1 | -19.1 | -32.3 | -12.0 | -7.3 | -233.3 | -11.3 | -19.7 | 0.0 | 0.0 | -16.2 | 0.0 | 0.0 | 0.0 | -1.6 | 0.0 | 0.0 | 0.0 | -13.6 | 0.0 | 0.0 | 0.0 | -226.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -1.9 | -16.5 | 1.4 | -3.2 | -3.5 | -3.9 | -104.1 | -4.5 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 3.8 | 106 | -536.6 | 1.2 | 4.6 | 606 | -30.1 | -20.9 | -21.1 | 532 | -34.2 | -54.2 | -1.1 | -843.8 | -27.8 | 49 | -64.3 | -17.0 | -41.9 | -9.1 | -75.8 | -75.1 | 19 | -27.009 | -82.242 | -101.105 | 379 | 12 | -48.316 | -21.598 | 31 | 169 | -31.199 | -24.801 | 128 | 0.073 | -32.89 | -30.704 | -33.32 | -25.638 | -31.79 | -54.945 | 150 | -0.517 |
| Percentage of NetCashProvidedByUsedInFinancingActivities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 0.7 | 32.9 | -192.9 | 0.4 | 2.5 | 239.9 | -10.7 | -6.8 | -4.4 | 200.8 | -15.6 | -24.5 | 0.0 | 0.0 | -15.5 | 0.0 | 0.0 | 0.0 | -15.1 | 0.0 | 0.0 | 0.0 | 7.2 | 0.0 | 0.0 | 0.0 | 225.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -12.1 | -22.2 | 6.1 | -15.4 | -12.7 | -41.8 | 109.8 | -0.4 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 215 | 74 | -558.6 | -19.4 | -45.5 | 602 | -91.3 | -11.7 | 88 | -15.9 | 3.4 | -124.6 | 61 | 148 |
| Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 41.9 | 23.0 | -200.8 | -5.7 | -24.6 | 238.0 | -32.5 | -3.8 | 18.5 | -6.0 | 1.6 | -56.3 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | -85.6 | -2.2 | 169 | -36.5 | -151.7 | 24 | 31 | -9.2 | -57.1 | 22 | -0.1 | 38 | -55.9 | 11 | -3.3 | -9.4 | 6.0 | 1.2 | -2.5 | -1.9 | 3.9 | -0.8 | 5.696 | -0.485 | -1.488 | -3.648 | 0.8 | -0.247 | -1.58 | -0.511 | -1.478 | -0.411 | -0.276 | -0.234 | 4.486 | 0.739 | -1.685 | -0.782 | -0.051 | -14.718 | -0.674 | -1.106 | 2.711 | -0.203 |
| Percentage of IncreaseDecreaseInOtherOperatingCapitalNet | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 230 | -19.8 | 4.6 | 60 | 33 | 43 | 29 | 45 | 144 | 70 | 62 | -26.9 | 106 | 55 | 54 | -6.9 | 96 | 74 | 37 | 22 | 100 | 66 | 41 | 29 | 104 | 89 | 27 | -4.843 | 67 | 51 | 30 | 14 | 53 | 46 | 42 | 6.059 | 40 | 55 | 41 | 26 | 44 | 60 | 4.516 | -2.545 |
| Percentage of NetCashProvidedByUsedInOperatingActivities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 44.7 | -6.1 | 1.7 | 17.9 | 18.0 | 17.2 | 10.5 | 15.0 | 30.2 | 26.5 | 28.5 | -12.2 | 0.0 | 0.0 | 30.2 | 0.0 | 0.0 | 0.0 | 13.6 | 0.0 | 0.0 | 0.0 | 15.2 | 0.0 | 0.0 | 0.0 | 16.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 15.1 | 39.9 | -7.6 | 16.1 | 17.8 | 46.0 | 3.3 | -1.7 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 108 | 36 | 17 | 43 | -118.8 | -23.4 | 4.0 | 14 | 107 | 11 | 11 | 56 | 103 | 182 | 38 | 16 | 78 | 7.3 | 26 | 8.7 | 69 | 2.8 | 7.508 | 4.203 | 55 | -1.558 | -13.807 | 3.531 | 57 | -0.7 | -5.705 | 9.249 | 50 | 1.058 | 2.374 | 5.973 | 48 | 1.353 | 7.613 | 19 | 40 | -3.185 | -1.895 | -0.689 | 27 |
| Percentage of NetIncomeLoss | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 21.0 | 11.1 | 6.1 | 12.8 | -64.2 | -9.3 | 1.4 | 4.8 | 22.4 | 4.4 | 5.2 | 25.4 | 0.0 | 0.0 | 21.4 | 0.0 | 0.0 | 0.0 | 9.6 | 0.0 | 0.0 | 0.0 | 2.8 | 0.0 | 0.0 | 0.0 | -8.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 17.9 | 1.0 | -1.4 | 11.9 | 16.1 | -2.4 | -1.4 | -0.5 | 12.8 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 108 | 36 | 17 | 43 | -118.8 | -23.5 | 3.7 | 14 | 107 | 11 |
| Percentage of ProfitLoss | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 21.0 | 11.1 | 6.1 | 12.8 | -64.2 | -9.3 | 1.3 | 4.8 | 22.4 | 4.4 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 64 | 44 | -17.9 | -3.0 |
| Percentage of ProfitLoss | 59.1 | 122.4 | 15.1 | 12.8 |
| Percentage of Revenues | 12.4 | 13.6 | -9.7 | -1.2 |
| Percentage of Revenues us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees | 32.3 | 31.9 | -263.2 | -2.2 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 108 | 36 | 43 | -118.8 | -23.4 | 14 | 107 | 11 |
| Percentage of ProfitLoss | 100.0 | 100.0 | 100.2 | 100.0 | 99.6 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 21.0 | 11.1 | 12.8 | -64.2 | -9.3 | 4.8 | 22.4 | 4.4 |
| Percentage of Revenues us-gaap:RetainedEarnings | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 7.1 | 5.5 | 6.4 | 6.9 | 6.1 | 4.3 | 6.2 | 5.5 | 7.4 | 4.7 | 4.6 | 3.9 | 6.4 | 6.1 | 9.6 | 5.8 | 6.7 | 4.9 | 4.6 | 4.9 | 5.3 | 4.1 | 3.22 | 4.5 | 3.4 | 2.723 | 1.364 | 2.213 | 3.113 | 5.241 | 5.915 | 5.99 | 6.214 | 3.363 | 1.53 | 1.669 | 4.715 | 1.924 | 1.199 | 1.366 | 1.435 | 1.531 | 2.414 | 0.802 |
| Percentage of ShareBasedCompensation | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | -18.2 | -12.3 | -26.6 | -81.0 | -83.5 | -48.3 | -90.6 | -36.7 | -34.8 | -619.1 | -24.8 | -43.5 | -44.3 | 936 | -29.0 | -27.3 | -45.9 | -51.4 | -4.5 | -10.6 | -20.6 | -15.0 | -37.131 | -10.382 | -12.888 | -5.084 | -380.885 | -12.211 | -19.335 | -27.877 | -60.93 | -178.418 | -22.721 | -19.803 | -164.074 | -7.92 | -5.146 | -22.848 | -7.784 | -5.333 | -8.861 | -5.083 | -142.869 | -6.656 |
| Percentage of NetCashProvidedByUsedInInvestingActivities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | -3.5 | -3.8 | -9.6 | -24.0 | -45.1 | -19.1 | -32.3 | -12.0 | -7.3 | -233.3 | -11.3 | -19.7 | 0.0 | 0.0 | -16.2 | 0.0 | 0.0 | 0.0 | -1.6 | 0.0 | 0.0 | 0.0 | -13.6 | 0.0 | 0.0 | 0.0 | -226.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -1.9 | -16.5 | 1.4 | -3.2 | -3.5 | -3.9 | -104.1 | -4.5 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 3.8 | 106 | -536.6 | 1.2 | 4.6 | 606 | -30.1 | -20.9 | -21.1 | 532 | -34.2 | -54.2 | -1.1 | -843.8 | -27.8 | 49 | -64.3 | -17.0 | -41.9 | -9.1 | -75.8 | -75.1 | 19 | -27.009 | -82.242 | -101.105 | 379 | 12 | -48.316 | -21.598 | 31 | 169 | -31.199 | -24.801 | 128 | 0.073 | -32.89 | -30.704 | -33.32 | -25.638 | -31.79 | -54.945 | 150 | -0.517 |
| Percentage of NetCashProvidedByUsedInFinancingActivities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Revenues | 0.7 | 32.9 | -192.9 | 0.4 | 2.5 | 239.9 | -10.7 | -6.8 | -4.4 | 200.8 | -15.6 | -24.5 | 0.0 | 0.0 | -15.5 | 0.0 | 0.0 | 0.0 | -15.1 | 0.0 | 0.0 | 0.0 | 7.2 | 0.0 | 0.0 | 0.0 | 225.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -12.1 | -22.2 | 6.1 | -15.4 | -12.7 | -41.8 | 109.8 | -0.4 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 0.0 | 24 | 0.0 | 0.0 | 0.0 | 23 | 0.0 | 0.0 | 0.0 | 22 | 0.2 | 0.0 | -0.2 | 23 | -0.3 | 0.0 | 0.0 | 21 | 0.0 | 0.0 | 0.0 | 19 | 0.0 | 0.0 | 0.0 | 17 | 0.0 | 0.0 | 0.0 | 15 | 0.0 | 0.0 | 0.0 | 0.0 | 12 | 0.0 | 0.0 | 10 | 0.0 | 0.0 | 0.0 | 8.165 | 0.0 | 0.0 |
| Percentage of PaymentsOfDividends | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 0.0 | 193 | 0.0 | 0.0 | 0.0 | 28 | 28 | 21 | 11 | 34 | 32 | 0.0 | 0.3 | 514 | 9.8 | 0.1 | 172 | 8.6 | 19 | 2.4 | 16 | 0.8 | 140 | 1.254 | 1.029 | 4.9 | 5.723 | 1.177 | 0.719 | 7.402 | 4.783 | 1.894 | 3.039 | 1.007 | 2.248 | 0.813 | 1.765 | 0.268 | 0.576 | 0.287 | 0.294 | 0.151 | -0.41 | 0.167 |
| Percentage of PaymentsForRepurchaseOfCommonStock | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 |
| Value | 0 | 27000.0 | -25000.0 | 0 | 0 | 37000.0 | 5000.0 | 0 |
| Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod | 0.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 |
| Value | 1000.0 | 62000.0 | 0 |
| Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod | 0.0 | 229.6 | 0.0 |
| Period End | 2020-09-30 |
| Value | 0 |
| Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 |
| Value | 213 | 212 | 78 | 40 | 153 | 127 | 131 |
| Percentage of DeferredTaxLiabilities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 60 | 24 | 18 | 19 | 33 | 62 | 68 | 43 | 44 | 48 |
| Percentage of DeferredTaxAssetsNet | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 | 2010-12-31 | 2009-12-31 |
| Value | 3900000.0 | 1800000.0 | 2800000.0 | 2900000.0 | 3100000.0 | 2500000.0 | 2926000.0 | 582000.0 | 8565000.0 | 2109000.0 | 2926000.0 | 2967000.0 |
| Percentage of UnrecognizedTaxBenefits | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 1400000.0 | 200000.0 | 200000.0 | 200000.0 | 500000.0 | 1052000.0 | 1274000.0 | 1213000.0 | 1334000.0 | 1487000.0 |
| Percentage of DeferredTaxAssetsValuationAllowance | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 |
| Value | 0.0 | 0.1 | 0.5 | 0.2 | 0.3 | 0.9 | 0.6 | 3.5 | 5.4 | 2.1 | 1.4 | 0.7 | 0.8 | 0.2 | -1.5 | 1.1 | 1.1 | 2.7 | 4.338 | 2.81 | 8.2 | 6.4 | 3.826 | 0.0 | 0.0 | 0.0 |
| Percentage of AcquisitionRelatedContingentConsiderationCosts | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 6.0 | 6.7 |
| Percentage of AdjustedEBITDASellingGeneralAdministrativeExpenses | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 3.0 | 1.7 |
| Percentage of AdjustedEBITDASellingGeneralAdministrativeExpenses | 50.0 | 25.4 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 2.2 | 1.4 |
| Percentage of AdjustedEBITDASellingGeneralAdministrativeExpenses | 36.7 | 20.9 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 2.6 | 1.2 | 1.5 | 2.1 | 2.0 | 1.7 | 0.8 | 1.2 | 1.0 |
| Percentage of AdjustedEBITDASellingGeneralAdministrativeExpenses | 0.0 | 0.0 | 22.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 5.9 | 8.3 | 3.9 | 6.7 | 7.9 | 6.9 | 6.4 | 4.5 | 4.0 | 3.8 |
| Percentage of AdjustedEBITDASellingGeneralAdministrativeExpenses | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 3.1 | 1.2 |
| Percentage of AdjustedEBITDASellingGeneralAdministrativeExpenses | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 3.6 | 1.7 | 1.4 | 1.8 | 1.9 | 1.8 | 1.4 | 1.6 | 1.4 |
| Percentage of AdjustedEBITDASellingGeneralAdministrativeExpenses | 0.0 | 0.0 | 20.9 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-06-30 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 |
| Value | 2.4 | 1.7 | 2.9 | 2.9 | 2.8 | 3.2 | 3.0 | 2.7 | 3.3 | 3.0 | 2.8 | 2.8 | 2.9 | 3.1 | 2.6 |
| Percentage of AdjustedEBITDASellingGeneralAdministrativeExpenses | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 |
| Value | 233 | 110 | 79 | 121 | 30 | 55 | 73 | 88 | 215 | 74 | 43 | 62 | 174 | 49 | 60 | 76 | 173 | 57 | 56 | 71 | 160 | 46 |
| Percentage of AdjustedEarningsBeforeInterestTaxDepreciationandAmortization | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | -8.0 | -10.4 |
| Percentage of AdjustedEarningsBeforeInterestTaxDepreciationandAmortization | -3.4 | -34.6 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 241 | 40 |
| Percentage of AdjustedEarningsBeforeInterestTaxDepreciationandAmortization | 103.4 | 134.6 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 119 | -1.8 |
| Percentage of AdjustedEarningsBeforeInterestTaxDepreciationandAmortization | 51.4 | -6.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 98 | 3.6 |
| Percentage of AdjustedEarningsBeforeInterestTaxDepreciationandAmortization | 42.2 | 12.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 23 | 38 |
| Percentage of AdjustedEarningsBeforeInterestTaxDepreciationandAmortization | 9.9 | 128.6 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 119 | -1.8 |
| Percentage of AdjustedEarningsBeforeInterestTaxDepreciationandAmortization | 51.4 | -6.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 98 | 3.6 |
| Percentage of AdjustedEarningsBeforeInterestTaxDepreciationandAmortization | 42.2 | 12.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 23 | 38 |
| Percentage of AdjustedEarningsBeforeInterestTaxDepreciationandAmortization | 9.9 | 128.6 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | -12.6 | -9.6 |
| Percentage of AdjustedSegmentEBITDA | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 123 | 131 | 41 | 65 | 91 | 220 | 83 | 62 | 178 | 58 |
| Percentage of AdjustedSegmentEBITDA | -977.8 | 0.0 | 0.0 | -686.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | -9.3 | -11.2 | -10.6 | -3.9 | -5.2 | -8.5 | -0.6 | -3.5 | -9.1 |
| Percentage of AdjustedSegmentEBITDA | 0.0 | 0.0 | 110.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 23 | 4.5 | 1.9 | 5.2 | 121 | 1.4 | -2.8 | 107 | -6.0 |
| Percentage of AdjustedSegmentEBITDA | 0.0 | 0.0 | -19.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 82 | 75 | -2.0 | 49 | 71 | 76 | 64 | 44 | 45 | 46 |
| Percentage of AdjustedSegmentEBITDA | -654.0 | 0.0 | 0.0 | -510.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 18 | 1.0 |
| Percentage of AdjustedSegmentEBITDA | -145.2 | -10.4 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 31 | 38 | 15 | 15 | 22 | 16 | 20 | 24 | 17 |
| Percentage of AdjustedSegmentEBITDA | 0.0 | 0.0 | -156.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 22 | 16 |
| Percentage of AdjustedSegmentEBITDA | -178.6 | -166.7 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 23 | 4.5 | 1.9 | 5.2 | 121 | 1.4 | -2.8 | 107 | -6.0 |
| Percentage of AdjustedSegmentEBITDA | 0.0 | 0.0 | -19.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 |
| Value | 82 | 75 | -2.0 | 49 | 71 | 76 | 64 | 44 | 45 | 46 | 24 | 26 | 27 | 18 | 20 | 19 | 21 | 16 | 12 | 14 |
| Percentage of AdjustedSegmentEBITDA | -654.0 | 0.0 | 0.0 | -510.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 18 | 1.0 |
| Percentage of AdjustedSegmentEBITDA | -145.2 | -10.4 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 31 | 38 | 15 | 15 | 22 | 16 | 20 | 24 | 17 |
| Percentage of AdjustedSegmentEBITDA | 0.0 | 0.0 | -156.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-31 | 2020-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 |
| Value | 22 | 16 | 19 | 23 | 16 | 18 | 19 | 13 | 14 | 18 | 12 | 9.867 | 13 | 16 | 11 | 10 | 11 | 14 | 9.95 |
| Percentage of AdjustedSegmentEBITDA | -178.6 | -166.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 |
| Value | -35.4 | -12.9 | -15.4 | -22.8 | -19.2 | -48.2 | -14.9 | -23.9 | -27.2 | -21.7 | -7.8 | 39 | -13.5 | -9.1 | -42.6 | -11.1 | -10.8 | -9.2 | 18 | -12.1 | -10.7 | -10.1 |
| Percentage of AdjustmentstoEarningsBeforeInterestTaxDepreciationandAmortization | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-12-31 |
| Value | 1200.0 |
| Percentage of BusinessCombinationFutureInvestmentInAcquisitionExtensionNumberOfHistoricalRacingMachines | 100.0 |
| Period End | 2020-12-31 |
| Value | 500.0 |
| Percentage of BusinessCombinationFutureInvestmentInAcquisitionExtensionNumberOfHistoricalRacingMachines | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-06-30 | 2019-03-31 |
| Value | 0.0 | 0.0 | 12 | 0.0 | 0.0 |
| Percentage of CashSettlementShareBasedPaymentArrangement | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 0.6 | 0.7 |
| Percentage of ContentExpense | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 46 | 32 |
| Percentage of ContentExpense | 7750.0 | 4657.1 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 0.2 | 0.1 | 0.4 | 0.5 | 0.8 | 0.5 | 0.5 | 0.9 | 0.4 |
| Percentage of ContentExpense | 0.0 | 0.0 | 57.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 1.3 | 1.3 | 0.4 | 1.2 | 1.6 | 1.7 | 1.2 | 0.9 | 1.1 | 0.9 |
| Percentage of ContentExpense | 0.0 | 0.0 | 0.0 | 171.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 0.8 | 0.1 |
| Percentage of ContentExpense | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 63 | 59 | 33 | 36 | 51 | 32 | 37 | 49 | 32 |
| Percentage of ContentExpense | 0.0 | 0.0 | 4742.9 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-06-30 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 |
| Value | 68 | 59 | 37 | 49 | 32 | 30 | 40 | 25 | 24 | 26 | 33 | 23 | 22 | 23 | 29 |
| Percentage of ContentExpense | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-02-01 | 2020-04-28 |
| Value | 226 | 26 |
| Percentage of DebtInstrumentRestrictiveCovenantsRestrictedPaymentCapacity | 100.0 | 100.0 |
| Period End | 2021-02-01 |
| Value | 226 |
| Percentage of DebtInstrumentRestrictiveCovenantsRestrictedPaymentCapacity | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 |
| Value | 5.2 | 3.7 | 2.6 | 2.1 | 0.8 | 7.6 | 8.7 | 8.9 | 7.9 | 7.8 | 6.6 | 6.6 |
| Percentage of DisclosureOfComplimentaryRevenue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-06-30 |
| Value | 0.0 | 124 | 0.0 |
| Percentage of DisposalGroupIncludingDiscontinuedOperationLegalSettlement | 0.0 | 100.0 | 0.0 |
| Period End | 2021-03-25 |
| Value | 124 |
| Percentage of DisposalGroupIncludingDiscontinuedOperationLitigationSettlement | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 |
| Value | 197 | 97 | 63 | 99 | 10 | 7.1 | 58 | 64 | 187 | 52 | 35 | 101 | 161 | 40 | 17 | 64 | 162 | 48 | 75 | 59 | 149 | 36 |
| Percentage of EarningsBeforeInterestTaxesDepreciationandAmortization | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 |
| Value | 10 | 9.6 | 9.9 | 9.8 | 9.5 | 9.7 | 9.7 | 3.5 | 3.6 | 4.3 | 4.3 | 4.0 | 3.1 | 3.5 | 2.5 | 2.5 | 2.5 | 2.5 | 2.1 | 2.2 | 2.2 |
| Percentage of EquityInvestmentsinterestdepreciationandamortizationexpense | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 |
| Value | 4.3 | 4.1 | 4.2 | 3.9 | 3.6 | 3.3 | 2.2 | 3.2 | 5.9 | 6.6 | 6.6 | 9.8 | 5.2 | 5.1 | 5.7 | 8.6 | 3.4 | 3.3 | 3.2 | 3.239 | 3.279 | 3.154 | 3.144 | 1.984 | 3.474 | 3.474 | 3.367 | 0.831 | 0.101 | -0.01 | 0.023 |
| Percentage of EquityMethodDepreciationAmortization | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 4.4 | 4.3 | 4.1 | 4.2 |
| Percentage of EquityMethodDepreciationAmortization | 0.0 | 0.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 |
| Value | 9.4 | 13 | 35 | 7.1 | 17 | 25 | 17 | 0.7 | 1.0 | 2.6 | 2.9 | 3.8 | -0.3 | 2.7 | 3.5 | 4.3 | 0.8 | 0.9 | 0.9 | 0.947 | 1.069 | 1.073 | 1.108 | 1.175 | 1.38 | 1.194 | 1.08 | -0.34 | 0.0 | 0.0 | 0.0 |
| Percentage of EquityMethodInvestmentInterest | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 19 | 4.6 | 13 | 35 |
| Percentage of EquityMethodInvestmentInterest | 0.0 | 0.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 |
| Value | 90 | 11 | 105 | 117 | 122 | 63 | 82 | 91 | 60 | 103 | 88 | 55 |
| Percentage of EquityMethodInvestmentOperatingExpense | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 114 | 89 | 11 | 105 |
| Percentage of EquityMethodInvestmentOperatingExpense | 0.0 | 0.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 |
| Value | 57 | -4.5 | 32 | 47 | 43 | 43 | 26 | 10 | 22 | 23 | 16 | 11 | 25 | 20 | 16 | 30 | 7.5 | 8.8 | 8.0 | 6.633 | 5.743 | 6.792 | 6.223 | 5.625 | 5.057 | 6.786 | 5.162 | -4.108 | -1.144 | -0.991 | -0.595 |
| Percentage of EquityMethodInvestmentOperatingIncomeLoss | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 83 | 48 | -4.5 | 32 |
| Percentage of EquityMethodInvestmentOperatingIncomeLoss | 0.0 | 0.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 |
| Value | 86 | 7.2 | 100 | 117 | 113 | 119 | 61 | 31 | 76 | 84 | 53 | -58.4 | 97 | 83 | 49 |
| Percentage of EquityMethodOperatingAndSellingGeneralAndAdministrativeExpenses | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 109 | 85 | 7.2 | 100 |
| Percentage of EquityMethodOperatingAndSellingGeneralAndAdministrativeExpenses | 0.0 | 0.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 |
| Value | -1.8 | -4.2 | -1.8 | -1.5 | 1.3 | 14 | -3.0 | 3.2 | 7.9 | 4.3 | 0.0 | 0.0 | 0.0 |
| Percentage of FairValueofInterestRateSwaps | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 1.4 | 5.3 |
| Percentage of Marketingandadvertising | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 2.1 | 1.2 |
| Percentage of Marketingandadvertising | 150.0 | 22.6 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 8.5 | 3.5 |
| Percentage of Marketingandadvertising | 607.1 | 66.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 2.3 | 0.3 | 1.1 | 1.1 | 3.6 | 1.1 | 0.6 | 3.2 | 0.3 |
| Percentage of Marketingandadvertising | 0.0 | 0.0 | 20.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 2.5 | 0.6 | 0.4 | 5.3 | 5.5 | 5.1 | 5.1 | 3.6 | 3.5 | 3.6 |
| Percentage of Marketingandadvertising | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 4.9 | 0.3 |
| Percentage of Marketingandadvertising | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 6.9 | 2.9 | 3.5 | 3.6 | 4.5 | 1.0 | 0.6 | 3.1 | 0.8 |
| Percentage of Marketingandadvertising | 0.0 | 0.0 | 66.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-06-30 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 |
| Value | 16 | 2.9 | 0.6 | 3.1 | 0.8 | 1.1 | 4.6 | 1.0 | 1.1 | 1.0 | 3.3 | 1.0 | 1.1 | 0.7 | 2.1 |
| Percentage of Marketingandadvertising | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 |
| Value | 65.34 |
| Percentage of MaximumGamingCapacityPercentage | 100.0 |
| Period End | 2020-09-30 |
| Value | 74.5 |
| Percentage of MaximumGamingCapacityPercentage | 114.0 |
| Period End | 2020-09-18 |
| Value | 63.0 |
| Percentage of MaximumGamingCapacityPercentage | 0.0 |
| Period End | 2020-09-30 |
| Value | 74.3 |
| Percentage of MaximumGamingCapacityPercentage | 113.7 |
| Period End | 2020-09-30 |
| Value | 65.34 |
| Percentage of MaximumGamingCapacitySlotsPercentage | 100.0 |
| Period End | 2020-09-30 |
| Value | 49.5 |
| Percentage of MaximumGamingCapacitySlotsPercentage | 75.8 |
| Period End | 2020-09-30 |
| Value | 59.4 |
| Percentage of MaximumGamingCapacitySlotsPercentage | 90.9 |
| Period End | 2020-09-30 |
| Value | 65.34 |
| Percentage of MaximumGamingCapacitySlotsPercentage | 100.0 |
| Period End | 2020-09-30 |
| Value | 74.34 |
| Percentage of MaximumGamingCapacitySlotsPercentage | 113.8 |
| Period End | 2020-09-30 |
| Value | 59.4 |
| Percentage of MaximumGamingCapacityTableGamesPercentage | 100.0 |
| Period End | 2020-09-30 |
| Value | 59.4 |
| Percentage of MaximumGamingCapacityTableGamesPercentage | 100.0 |
| Period End | 2020-09-30 |
| Value | 59.4 |
| Percentage of MaximumGamingCapacityTableGamesPercentage | 100.0 |
| Period End | 2020-09-30 |
| Value | 59.4 |
| Percentage of MaximumGamingCapacityTableGamesPercentage | 100.0 |
| Period End | 2020-09-30 |
| Value | 59.4 |
| Percentage of MaximumGamingCapacityTableGamesPercentage | 100.0 |
| Period End | 2020-09-30 |
| Value | 44.4 |
| Percentage of MaximumGamingCapacityTableGamesPercentage | 74.7 |
| Period End | 2020-09-30 |
| Value | 69.3 |
| Percentage of MaximumGamingCapacityVideoLotteryTerminalsPercentage | 100.0 |
| Period End | 2020-09-30 |
| Value | 66.5 |
| Percentage of MaximumGamingCapacityVideoLotteryTerminalsPercentage | 96.0 |
| Period End | 2020-09-30 |
| Value | 74.5 |
| Percentage of MaximumPatronCapacityPercentage | 100.0 |
| Period End | 2020-09-30 |
| Value | 24.75 |
| Percentage of MaximumPatronCapacityPercentage | 33.2 |
| Period End | 2020-09-30 |
| Value | 49.5 |
| Percentage of MaximumPatronCapacityPercentage | 66.4 |
| Period End | 2020-09-30 |
| Value | 49.5 |
| Percentage of MaximumPatronCapacityPercentage | 66.4 |
| Period End | 2020-09-18 |
| Value | 75.0 |
| Percentage of MaximumPatronCapacityPercentage | 0.0 |
| Period End | 2020-09-30 |
| Value | 49.5 |
| Percentage of MaximumPatronCapacityPercentage | 66.4 |
| Period End | 2020-09-30 |
| Value | 49.5 |
| Percentage of MaximumPatronCapacityPercentage | 66.4 |
| Period End | 2020-09-30 |
| Value | 49.5 |
| Percentage of MaximumPatronCapacityPercentage | 66.4 |
| Period End | 2020-09-30 |
| Value | 49.5 |
| Percentage of MaximumPatronCapacityPercentage | 66.4 |
| Period End | 2020-10-02 |
| Value | 75.0 |
| Percentage of MaximumPatronCapacityPercentage | 0.0 |
| Period End | 2020-09-30 |
| Value | 62.5 |
| Percentage of MaximumPatronCapacityPercentage | 83.9 |
| Period End | 2020-09-30 |
| Value | 24.5 |
| Percentage of MaximumPatronCapacityPercentage | 32.9 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 |
| Value | 108 | 36 | 17 | 43 | -118.8 | -23.4 | 4.0 | 14 | 107 | 11 | 11 | 56 | 103 | 182 | 38 | 16 | 78 | 7.3 | 26 | 8.7 | 69 | 2.8 | 7.497 | 4.2 | 55 | -13.807 | 3.531 | 57 | -0.7 | -5.705 | 9.249 | 50 | 1.058 | 2.374 | 5.973 | 48 | 1.353 | 7.613 | 19 | 40 |
| Percentage of NetEarningsAndComprehensiveIncome | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 |
| Value | 0 | 11000.0 | 0 |
| Percentage of NumberOfSlotMachines | 0.0 | 100.0 | 0.0 |
| Period End | 2020-09-26 |
| Value | 30.0 |
| Percentage of NumberOfSpectatorFreeLiveRacingDaysHeld | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 |
| Value | 2500000.0 | 200000.0 | 1300000.0 | 1200000.0 | 1300000.0 | 1200000.0 | 1300000.0 | 1100000.0 |
| Percentage of OperatingLeaseAssetAmortization | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 31 | 21 |
| Percentage of OtherincomeexpenseAdjustedEBITDA | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 51 | 35 | -0.1 | 21 | 27 | 27 | 15 | 12 | 12 | 10 |
| Percentage of OtherincomeexpenseAdjustedEBITDA | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 |
| Value | 0.1 |
| Percentage of OtherincomeexpenseAdjustedEBITDA | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 0.0 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of OtherincomeexpenseAdjustedEBITDA | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 |
| Value | 60.0 |
| Percentage of PatronCapacityPercentage | 100.0 |
| Period End | 2021-06-30 |
| Value | 40.0 |
| Percentage of PatronCapacityPercentage | 66.7 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 |
| Value | 0.8 | 4.2 | 2.4 | -17.6 | -8.4 | 36 | 2.2 | 3.4 | 3.1 | 3.7 | -4.8 | -10.5 | 15 | 6.3 | 4.0 | 5.6 | 0.0 | 0.0 | 4.2 |
| Percentage of PropertyAndEquipmentAdditionsIncludedInAccountsPayableAndAccruedExpenses | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 19 | 29 |
| Percentage of Salariesandbenefits | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 10.0 | 7.2 |
| Percentage of Salariesandbenefits | 50.3 | 24.4 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 3.1 | 3.5 |
| Percentage of Salariesandbenefits | 15.6 | 11.9 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 8.4 | 4.9 | 6.2 | 6.8 | 12 | 5.2 | 4.5 | 9.7 | 3.1 |
| Percentage of Salariesandbenefits | 0.0 | 0.0 | 21.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 20 | 19 | 9.0 | 29 | 26 | 25 | 24 | 16 | 15 | 16 |
| Percentage of Salariesandbenefits | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 15 | 5.3 |
| Percentage of Salariesandbenefits | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 3.1 | 3.0 | 3.5 | 3.0 | 2.7 | 2.5 | 2.1 | 2.4 | 2.1 |
| Percentage of Salariesandbenefits | 0.0 | 0.0 | 11.9 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-06-30 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 |
| Value | 3.2 | 3.0 | 2.1 | 2.4 | 2.1 | 2.3 | 2.6 | 2.2 | 2.5 | 2.3 | 2.3 | 2.3 | 2.4 | 2.6 | 2.4 |
| Percentage of Salariesandbenefits | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 59 | 58 |
| Percentage of Taxesandpurses | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 20 | 9.5 |
| Percentage of Taxesandpurses | 33.7 | 16.2 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 6.4 | 4.3 |
| Percentage of Taxesandpurses | 10.8 | 7.3 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 19 | 13 | 7.1 | 10 | 35 | 6.2 | 3.6 | 27 | 0.7 |
| Percentage of Taxesandpurses | 0.0 | 0.0 | 12.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 70 | 51 | 14 | 59 | 71 | 68 | 65 | 37 | 35 | 38 |
| Percentage of Taxesandpurses | 0.0 | 0.0 | 0.0 | 100.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 50 | 14 |
| Percentage of Taxesandpurses | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 8.0 | 6.6 | 3.9 | 4.4 | 4.3 | 3.3 | 4.2 | 4.6 | 3.4 |
| Percentage of Taxesandpurses | 0.0 | 0.0 | 6.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-06-30 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 |
| Value | 8.3 | 6.7 | 4.2 | 4.6 | 3.4 | 4.5 | 4.1 | 3.0 | 2.9 | 4.0 | 2.0 | 2.8 | 2.4 | 3.6 | 2.7 |
| Percentage of Taxesandpurses | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 |
| Value | 0.0 | 0.1 | 0.0 | 0.5 | 0.2 | 0.3 | 0.3 | 0.9 | 0.6 | 3.5 | 1.4 | 5.4 | 2.1 | 1.4 | 1.2 | 0.6 |
| Percentage of Transactionexpensenet | 0.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 7100000.0 | 5500000.0 | 6100000.0 | 4300000.0 |
| Percentage of AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 7100000.0 | 5500000.0 | 6100000.0 | 4300000.0 |
| Percentage of AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2015-09-30 | 2014-12-31 | 2014-09-30 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 11 | 21 | 0.0 | -0.248 | 12 | 4.843 | 0.0 | 0.0 | 0.025 | -1.369 | 1.369 | 0.212 | 0.325 | 0.097 | 0.06 | 0.0 | 0.0 |
| Percentage of AssetImpairmentCharges | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 |
| Value | 11 |
| Percentage of AssetImpairmentCharges | 100.0 |
| Period End | 2021-12-31 |
| Value | 200 |
| Percentage of BusinessCombinationConsiderationTransferred1 | 100.0 |
| Period End | 2020-12-31 |
| Value | 200 |
| Percentage of BusinessCombinationConsiderationTransferred1 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 |
| Value | 28 | 2.6 | 0.9 | 1.7 | 0.3 | 3.8 | 1.6 | 1.1 | 45 | 2.7 | 2.4 | 1.2 | 47 |
| Percentage of ContractWithCustomerLiabilityRevenueRecognized | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 26 | 26 | 26 | 22 | 22 | 22 | 32 | 22 | 21 | 20 | 17 | 16 | 15 | 13 | 23 | 24 | 24 | 24 | 27 | 27 | 26 | 27 | 27 | 27 | 27 | 27 | 19 | 17 | 15 | 15 | 15 | 15 | 14 | 15 | 14 | 13 | 13 | 13 | 13 | 13 | 13 | 13 | 12 | 12 |
| Percentage of DepreciationAndAmortization | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 |
| Value | 0.0 | -124.3 | -1.2 | -0.8 | -1.6 | -0.4 | -0.7 | -0.6 | 219 | 4.8 | 6.1 | 9.0 |
| Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodBeforeIncomeTax | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 |
| Value | 0.0 | -95.2 | -0.9 | -0.4 | -1.2 | -0.3 | -1.7 | -0.1 | 167 | 3.6 | 5.6 | 5.1 |
| Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 |
| Value | 0.02 | 0 | -2.41 | -20000.0 | -0.01 | -0.01 | -0.03 | -0.01 | 0.1 | -0.12 | -0.02 | 11.58 | 0.24 | 0.24 | 0.34 | 0.31 | 0.44 | 0.32 | 0.18 | -0.26 |
| Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 |
| Value | 0.0 | -29.1 | -0.3 | -0.4 | -0.4 | -0.1 | 1.0 | -0.5 | 51 | 1.2 | 0.5 | 3.9 |
| Percentage of DiscontinuedOperationTaxEffectOfIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriod | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 |
| Value | 0.0 | 0.3 | 1.2 | 0.8 | 1.6 | 0.4 | 0.7 | 0.6 | 4.3 | 6.7 | 6.7 | 5.5 |
| Percentage of DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 |
| Value | 25 | 22 | 17 | 8.0 | 3.5 | 1.3 | 13 | 13 | 5.5 | 6.0 | 5.4 | 4.5 | 5.4 | 4.5 | 6.3 | 3.0 | 4.4 | 4.3 | 3.3 | 4.1 | 4.2 | 4.0 | 4.25 | 3.5 | 4.0 | 3.5 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of EquityMethodInvestmentDividendsOrDistributions | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 |
| Value | 12 | 10.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 |
| Percentage of EquityMethodInvestmentDividendsOrDistributions | 47.1 | 45.5 | 74.1 | 88.9 | 133.3 | 90.9 | 93.0 | 97.6 | 95.2 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 13 | 12 | 0.0 | 1.3 |
| Percentage of EquityMethodInvestmentDividendsOrDistributions | 52.2 | 54.5 | 0.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 |
| Value | 48 | -17.9 | -3.0 | 40 | 25 | 18 | 9.3 | 9.8 | 21 | 20 | 13 | 7.2 | 25 | 17 | 13 | 26 | 6.7 | 7.9 | 7.1 | 5.686 | 4.674 | 5.719 | 5.115 | 4.45 | 3.677 | 5.592 | 4.082 | -4.448 | -1.144 | -0.991 | -0.595 |
| Percentage of EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 |
| Value | 148 | 6.8 | 137 | 168 | 160 | 166 | 89 | 45 | 105 | 114 | 77 | -37.6 | 128 | 109 | 72 | 102 | 37 | 38 | 38 | 34 | 33 | 34 | 34 | 28 | 34 | 36 | 32 | 7.443 | 1.305 | 1.763 | 1.441 |
| Percentage of EquityMethodInvestmentSummarizedFinancialInformationRevenue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 |
| Value | 0 |
| Percentage of GoodwillPurchaseAccountingAdjustments | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-06-30 | 2019-03-31 |
| Value | 0.0 | 0.0 | 0.0 | 17 | 0.0 | 0.0 |
| Percentage of ImpairmentOfIntangibleAssetsExcludingGoodwill | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2014-03-31 | 2013-09-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 |
| Value | 0.7 | 0.0 | -95.2 | -0.9 | -0.5 | -0.4 | -1.2 | -0.3 | 4.1 | -1.7 | -0.1 | 167 | 3.8 | 3.8 | 5.4 | 5.1 | 7.4 | 5.3 | 3.0 | -4.3 | 0.1 | 0.1 | 0.1 | 0.0 | 0.0 | 0.0 | 3.342 | 0.06 | 0.157 |
| Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2013-12-31 | 2013-09-30 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 0.02 | 0 | -2.41 | -20000.0 | -0.01 | -0.01 | -0.03 | -0.01 | 0.1 | -0.12 | -0.01 | 11.63 | 0.25 | 0.24 | 0.34 | 0.31 | 0.45 | 0.32 | 0.19 | -0.26 | -0.02 | 0 | 0 | 0 | 0 | 0.2 | 0 | 0.01 | 0.15 | -0.26 | -0.05 |
| Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 36 | 24 | 14 | 27 | -11.1 | -3.3 | 22 | 14 | 9.5 | 4.1 | 5.2 | 9.1 | 8.8 | 6.5 | 2.8 | 8.9 | 7.7 | 6.1 | 3.9 | 4.9 | 4.8 | 3.8 | 2.936 | 2.389 | 2.907 | 2.948 | 0.475 | 1.057 | 2.506 | 2.29 | -2.46 | -0.887 | -0.631 | -0.164 | -0.446 | -0.471 | -0.564 | -0.22 | -0.69 | -0.467 | 0.46 | -0.416 | -0.254 | -0.47 | -0.29 |
| Percentage of IncomeLossFromEquityMethodInvestments | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 |
| Value | 36 | 24 | 27 | -11.1 | -3.3 | 22 | 14 | 9.5 | 4.1 | 5.0 | 9.1 | 8.8 | 6.5 | 1.839 | 2.796 | 2.041 | -0.572 | -0.495 | -0.298 |
| Percentage of IncomeLossFromEquityMethodInvestments | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 99.6 | 100.0 | 100.0 | 100.0 | 96.2 | 100.0 | 100.0 | 100.0 | 174.0 | 111.6 | 89.1 | 64.5 | 78.4 | 181.7 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-09-30 | 2010-09-30 |
| Value | 30 | 9.2 | -3.8 | -11.7 | -10.7 | -16.4 | 31 | 0.3 | -24.1 | 2.9 | 52 | -25.5 | 43 | 6.6 | -7.7 | 41 | -5.7 | -20.978 | 46 | 12 | -18.485 | 32 | 6.03 | -19.458 | 29 | -0.46 | -18.844 | 30 | 0.11 | -3.537 | -7.244 |
| Percentage of IncreaseDecreaseInAccruedIncomeTaxesPayable | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 |
| Value | -1.7 | -5.7 | -17.4 | 22 | 1.9 | -9.9 | -5.7 | -6.4 | -17.8 | -4.8 | -2.1 | 13 | 0.0 | 0.0 |
| Percentage of IncreaseDecreaseInDeferredIncomeTaxes | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | -33.6 | 21 | -6.400000000000001 | -45.4 | -9.9 | 53 | 26 | 0.9 | -83.1 | 46 | 33 | 0.1 | -79.5 | 35 | 44 | 7.5 | -77.3 | 42 | 25 | -3.3 | -58.1 | 53 | 25 | 12 | -55.517 | 55 | 25 | 1.046 | -58.942 | 33 | 23 | -0.83 | -53.648 | 37 | 16 | -0.628 | -45.843 | 38 | -38.98 | -1.185 | -34.468 | 37 | 14 | -13.666 |
| Percentage of IncreaseDecreaseInDeferredRevenue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 |
| Value | 0.0 | -124.0 |
| Percentage of IncreaseDecreaseInOtherOperatingLiabilities | 0.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 |
| Value | 600000.0 | 600000.0 | 600000.0 | 0 | 0 | 0 | 700000.0 | 600000.0 | 200000.0 | 200000.0 | 100000.0 | 100000.0 | 100000.0 | 0 | 200000.0 | 200000.0 | 200000.0 | 0 | 200000.0 | 200000.0 | 200000.0 | 5000.0 | 139000.0 | 112000.0 | 0 | -14000.0 | 102000.0 | 140000.0 | 0 | 9000.0 | 254000.0 | 242000.0 | 222000.0 | -3000.0 | 220000.0 | 268000.0 | 222000.0 | 13000.0 | 116000.0 | 109000.0 |
| Percentage of IncrementalCommonSharesAttributableToShareBasedPaymentArrangements | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2019-12-31 | 2019-09-30 | 2018-12-31 | 2018-09-30 |
| Value | 6700000.0 | 1300000.0 | 0 | 3300000.0 | 0 | 0 |
| Percentage of LegalFees | 100.0 | 100.0 | 0.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 |
| Value | -3000000.0 |
| Percentage of MinorityInterestDecreaseFromRedemptions | 100.0 |
| Period End | 2020-09-30 |
| Value | -2500000.0 |
| Percentage of MinorityInterestDecreaseFromRedemptions | 83.3 |
| Period End | 2020-09-30 |
| Value | -500000.0 |
| Percentage of MinorityInterestDecreaseFromRedemptions | 16.7 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 |
| Value | 108 | 36 | 16 | 43 | -23.6 | -22.5 | 4.5 | 15 | 108 | 11 | 7.3 | 58 | 103 | 14 | 34 | 13 | 72 | 2.2 |
| Percentage of NetIncomeLossFromContinuingOperationsAvailableToCommonShareholdersDiluted | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 15 | 19 |
| Percentage of OtherCostAndExpenseOperating | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 10 | 7.8 |
| Percentage of OtherCostAndExpenseOperating | 69.0 | 40.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 10 | 8.1 |
| Percentage of OtherCostAndExpenseOperating | 70.3 | 41.5 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 11 | 5.3 | 5.6 | 6.9 | 16 | 5.3 | 4.6 | 14 | 2.8 |
| Percentage of OtherCostAndExpenseOperating | 0.0 | 0.0 | 28.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 17 | 14 | 11 | 19 | 21 | 21 | 19 | 14 | 15 | 13 |
| Percentage of OtherCostAndExpenseOperating | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 17 | 5.8 |
| Percentage of OtherCostAndExpenseOperating | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 9.4 | 9.0 | 7.2 | 6.1 | 8.6 | 5.8 | 5.7 | 8.2 | 5.8 |
| Percentage of OtherCostAndExpenseOperating | 0.0 | 0.0 | 36.9 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-06-30 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 |
| Value | 13 | 9.7 | 5.7 | 8.2 | 5.8 | 5.3 | 7.0 | 4.8 | 4.2 | 4.5 | 6.2 | 5.0 | 3.9 | 4.2 | 5.4 |
| Percentage of OtherCostAndExpenseOperating | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | -1900000.0 | -1200000.0 | -1000000.0 | -1700000.0 | -900000.0 | -900000.0 | -800000.0 | -900000.0 | -700000.0 | -400000.0 | -600000.0 | -500000.0 | -800000.0 | -900000.0 | -700000.0 | -300000.0 | -400000.0 | -300000.0 | -500000.0 | -400000.0 | -400000.0 | -700000.0 | -3452000.0 | -403000.0 | -402000.0 | -402000.0 | -161000.0 | -156000.0 | -153000.0 | -149000.0 | -134000.0 | -134000.0 | -177000.0 | -244000.0 | -242000.0 | -213000.0 | -227000.0 | -228000.0 | -4628000.0 | 149000.0 | 2261000.0 | -271000.0 | -2665000.0 | 444000.0 |
| Percentage of OtherNoncashIncomeExpense | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 |
| Value | 400000.0 |
| Percentage of OtherNonoperatingExpense | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 0.1 | 0.1 | 0.3 | 0.4 | 0.2 | 0.4 | 0.0 | 0.2 | 0.1 | 0.3 | 0.1 | 6.196 | -0.186 | 0.028 | -0.188 | 0.137 | 0.114 | 0.393 | -0.025 | 0.199 | 4.438 | 1.023 | 0.007 | 0.18 | 0.569 | 0.037 | 0.033 | 0.094 | 19 | 3.158 | 0.457 | 0.412 | 1.832 | 0.359 |
| Percentage of OtherNonoperatingIncome | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 |
| Value | 200000.0 | 800000.0 | -100000.0 | 0 | 0 | 500000.0 | 200000.0 | 0 | 0 | 400000.0 | 0 | 200000.0 | -900000.0 | 3100000.0 | 300000.0 | 0 | 0 | 0 | 0 |
| Percentage of OtherSellingGeneralAndAdministrativeExpense | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 8.3 | 7.6 | 19 | 73 | 78 | 39 | 29 | 20 | 18 | 14 |
| Percentage of PaymentsForCapitalImprovements | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2016-12-31 | 2016-09-30 |
| Value | 2.5 | 2.2 | 0.5 | 0.0 | 0.1 | 2.2 | -11.0 | 9.9 | 0.9 | 3.5 | 5.9 | 0.0 | 2.4 | -0.1 | 0.4 | -1.5 |
| Percentage of PaymentsForProceedsFromOtherInvestingActivities | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 |
| Value | 1.0 | 5.8 | 0.3 | 0.0 | 0.8 | 0.9 | 0.0 | 0.3 | 1.1 | 7.5 | 0.8 | 0.0 | 0.0 | 0.0 | 4.6 | 0.0 | 0.0 | 0.0 | 0.003 | 0.0 | 0.0 | 1.029 | 5.25 | 0.0 | 0.0 | 0.0 |
| Percentage of PaymentsOfDebtIssuanceCosts | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 0.0 | 12 | 3.6 | 0.0 | 0.0 | 15 | 3.8 | 0.1 | 0.0 | 7.6 | 2.7 |
| Percentage of PaymentsRelatedToTaxWithholdingForShareBasedCompensation | 0.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 |
| Period End | 2020-10-02 |
| Value | 38 |
| Percentage of PaymentsToAcquireBusinessesGross | 100.0 |
| Period End | 2020-09-11 |
| Value | 3.0 |
| Percentage of PaymentsToAcquireBusinessesGross | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 9.0 | 4.7 | 4.8 | 5.0 | 4.2 | 9.0 | 10 | 11 | 12 | 13 |
| Percentage of PaymentsToAcquireOtherPropertyPlantAndEquipment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 |
| Value | 1.5 | 0.6 | 6.2 | 1.9 | 1.7 | 1.2 | 0.9 | 1.3 | 2.6 | 0.7 | 0.6 | 0.0 | 0.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.027 | 2.409 | 0.5 | 0.48 | 0.23 | 0.0 | 0.0 | 0.0 |
| Percentage of PreOpeningCosts | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 0.0 | 780 | -0.1 | 6.3 | 719 | 0.7 | 3.4 | 1231 | 12 | 16 | 100 | 225 | 304 | 239 | 162 | 122 | 150 | 292 | 321 | 192 | 114 | 75 | 487 | 106 | 117 | 93 | 98 | 290 | 247 | 103 | 262 | 109 | 103 | 79 | 89 | 72 | 84 | 72 | 238 | 71 |
| Percentage of ProceedsFromLinesOfCredit | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | -27.2 | -51.7 | 700 |
| Percentage of ProceedsFromLinesOfCredit | 27200.0 | -820.6 | 97.4 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 |
| Value | -200000.0 | 1600000.0 | -200000.0 | 2300000.0 | 100000.0 | -100000.0 | 2900000.0 | 1800000.0 | 0 | -2300000.0 | -1400000.0 | 1400000.0 | 100000.0 | -4500000.0 | -900000.0 | -4400000.0 | 5200000.0 | -1400000.0 | 100000.0 | -500000.0 | 2800000.0 | 3000000.0 | -5167000.0 | -200000.0 | 4500000.0 | 800000.0 |
| Percentage of ProceedsFromPaymentsForOtherFinancingActivities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 |
| Value | 6.7 | -12.8 |
| Percentage of ProceedsFromRepaymentsOfBankOverdrafts | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 17 | 12 | 24 | 78 | 83 | 48 | 40 | 32 | 30 | 28 | 23 | 53 | 38 | 34 | 27 | 25 | 26 | 37 | 10 | 9.6 | 18 | 16 | 12 | 8.157 | 12 | 9.784 | 5.632 | 10 | 18 | 20 | 18 | 6.086 | 10 | 13 | 15 | 8.983 | 25 | -9.12 | -5.865 | -5.935 | -5.35 | -5.517 | -5.459 | -4.345 |
| Percentage of PropertyPlantAndEquipmentAdditions | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 |
| Value | 0.6 | 1.8 |
| Percentage of PropertyPlantAndEquipmentAdditions | 4.9 | 3.7 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 65 | 63 | 29 | 24 | 24 | -0.7 | 4.5 | 4.8 | 1.6 | 1.5 | 1.5 |
| Percentage of PropertyPlantAndEquipmentAdditions | 83.2 | 76.1 | 60.7 | 61.4 | 76.1 | -2.3 | 16.0 | 20.1 | 3.0 | 3.9 | 4.4 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 0.9 | 9.1 | 16 | 12 | 6.7 | 2.8 | 12 | 9.6 | 9.0 | 44 | 29 | 26 |
| Percentage of PropertyPlantAndEquipmentAdditions | 3.7 | 11.5 | 19.4 | 25.1 | 16.7 | 8.7 | 40.1 | 34.2 | 37.7 | 83.5 | 78.3 | 77.1 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 |
| Value | 4.9 | 1.6 | 1.4 | 0.6 | 1.2 | 3.3 | 6.4 | 2.5 | 25 | 2.5 | 7.5 | 4.6 |
| Percentage of PropertyPlantAndEquipmentAdditions | 28.3 | 13.0 | 5.8 | 0.8 | 1.4 | 6.8 | 15.9 | 7.8 | 83.7 | 8.9 | 31.4 | 8.6 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 9.1 | 7.8 | 78 | 39 |
| Percentage of PropertyPlantAndEquipmentAdditions | 52.6 | 63.4 | 94.2 | 82.2 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 2.0 | 3.5 | 2.5 | 3.6 | 2.4 | 2.4 | -6.6 | 11 | 2.6 | 2.4 | 2.4 | 2.3 |
| Percentage of PropertyPlantAndEquipmentAdditions | 8.3 | 4.4 | 3.0 | 7.5 | 6.0 | 7.5 | -21.5 | 40.9 | 10.9 | 4.5 | 6.3 | 6.8 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 2.2 | 2.3 | 2.6 | 3.5 |
| Percentage of PropertyPlantAndEquipmentAdditions | 12.7 | 18.7 | 3.1 | 7.2 |
| Period End | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 11 | 13 | 19 | 19 | 15 | 7.7 | 31 | 23 | 19 | 51 | 36 | 32 |
| Percentage of PropertyPlantAndEquipmentAdditions | 95.1 | 16.8 | 23.9 | 39.3 | 38.6 | 23.9 | 102.3 | 84.0 | 79.9 | 96.6 | 96.6 | 95.6 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 1.7 | 425 | 1.0 | 1.0 | 32 | 1.7 | 4.4 | 632 | 13 | 17 | 343 | 173 | 201 | 192 | 161 | 128 | 211 | 87 | 420 | 219 | 200 | 146 | 100 | 91 | 114 | 96 | 354 | 119 | 281 | 125 | 122 | 101 | 148 | 98 | 118 | 101 | 122 | 114 | 106 | 75 |
| Percentage of RepaymentsOfLinesOfCredit | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2019-09-30 | 2019-03-31 | 2018-03-31 |
| Value | 100000.0 | 0 | -100000.0 | -100000.0 |
| Percentage of RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings | 100.0 | 0.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2020-06-30 |
| Value | 3.9 | 2.8 |
| Percentage of RevenueFromRelatedParties | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | -18.8 | -6.6 | -7.8 | -11.8 | -10.2 | -5.2 | -6.0 | -5.2 | -14.9 | -4.2 | -4.7 | -4.6 | -13.5 | -4.1 |
| Percentage of RevenueFromRelatedParties | -482.1 | 0.0 | 0.0 | 0.0 | -364.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 2.7 | 4.0 | 2.9 | 3.0 | 2.6 | 3.4 | 3.4 | 2.2 | 2.0 | 3.2 | 3.6 | 2.4 |
| Percentage of RevenueFromRelatedParties | 0.0 | 0.0 | 103.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 3.3 | 7.2 | 6.9 | 0.3 | 2.6 | 1.3 | 10 | 0.4 | 2.0 | 1.0 | 9.4 | 0.3 |
| Percentage of RevenueFromRelatedParties | 0.0 | 0.0 | 246.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 0.0 | 2.0 | 0.9 | 0.1 | 0.0 | 1.5 | 0.6 | 0.3 | 0.2 | 1.3 | 0.5 | 0.1 | 0.1 | 1.0 |
| Percentage of RevenueFromRelatedParties | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 14 | 1.5 | 7.0 | 1.0 |
| Percentage of RevenueFromRelatedParties | 374.4 | 0.0 | 250.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 0.3 | 0.5 | 0.4 | 0.4 | 0.2 | 0.2 | 0.4 | 0.3 | 0.2 | 0.3 | 0.4 | 0.4 |
| Percentage of RevenueFromRelatedParties | 0.0 | 0.0 | 14.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 0.3 | 0.4 | 0.4 | 0.3 |
| Percentage of RevenueFromRelatedParties | 7.7 | 0.0 | 14.3 | 0.0 |
| Period End | 2021-02-01 |
| Value | 193 |
| Percentage of SaleOfStockConsiderationReceivedOnTransaction | 100.0 |
| Period End | 2021-02-01 |
| Value | 1000000.0 |
| Percentage of SaleOfStockNumberOfSharesIssuedInTransaction | 100.0 |
| Period End | 2021-03-31 | 2020-09-30 | 2019-09-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 100000.0 | 100000.0 | 100000.0 | 100000.0 | 0 | 100000.0 | 100000.0 |
| Percentage of StockIssuedDuringPeriodSharesNewIssues | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2019-09-30 |
| Value | 2.5 | 1.9 |
| Percentage of StockIssuedDuringPeriodValueOther | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2019-09-30 |
| Value | 2.5 | 1.9 |
| Percentage of StockIssuedDuringPeriodValueOther | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 | 2019-09-30 | 2019-03-31 | 2018-03-31 |
| Value | 12 | 15 | 0.1 | 7.6 | 12 |
| Percentage of StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 | 2019-09-30 | 2019-03-31 | 2018-03-31 |
| Value | 12 | 15 | 0.1 | 7.6 | 12 |
| Percentage of StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-02-01 |
| Value | 1000000.0 |
| Percentage of StockRepurchasedDuringPeriodShares | 100.0 |
| Period End | 2021-03-31 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-06-30 | 2018-03-31 |
| Value | 1000000.0 | 300000.0 | 200000.0 | 200000.0 | 300000.0 | 0 | 5800000.0 |
| Percentage of StockRepurchasedDuringPeriodShares | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-31 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-06-30 | 2018-03-31 |
| Value | 193 | 27 | 25 | 18 | 32 | 0.3 | 514 |
| Percentage of StockRepurchasedDuringPeriodValue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 0.0 | 0.0 | 0.0 | 27 | 25 | 25 | 43 | 25 |
| Percentage of StockRepurchasedDuringPeriodValue | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 100.0 | 238.9 | 76.7 |
| Period End | 2021-02-01 |
| Value | 193 |
| Percentage of StockRepurchasedDuringPeriodValue | 0.0 |
| Period End | 2021-03-31 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-06-30 | 2018-03-31 |
| Value | 22 | 4.3 | 10 | 4.4 | 4.7 | 0.3 | 13 |
| Percentage of StockRepurchasedDuringPeriodValue | 11.3 | 15.4 | 41.6 | 24.4 | 14.4 | 100.0 | 2.6 |
| Period End | 2021-03-31 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-03-31 |
| Value | 171 | 23 | 14 | 13 | 27 | 500 |
| Percentage of StockRepurchasedDuringPeriodValue | 88.7 | 84.6 | 58.4 | 75.6 | 85.6 | 97.4 |
| Period End | 2021-06-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 200000.0 | 200000.0 | 0 | -100000.0 | 200000.0 | -200000.0 | -200000.0 | 400000.0 |
| Percentage of StockholdersEquityOther | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2020-06-30 | 2019-09-30 | 2019-03-31 | 2018-09-30 | 2018-06-30 |
| Value | 200000.0 | 200000.0 | -100000.0 | 200000.0 | -300000.0 | -100000.0 |
| Percentage of StockholdersEquityOther | 100.0 | 100.0 | 0.0 | 100.0 | 150.0 | 50.0 |
| Period End | 2020-12-31 |
| Value | -800000.0 |
| Percentage of TaxCutsAndJobsActOf2017ChangeInTaxRateDeferredTaxAssetIncomeTaxExpense | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2018-12-31 |
| Value | 54 | 40 | 38 | 41 | 38 | 32 | 28 | 29 |
| Percentage of AccountWageringDepositsLiabilityCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2018-12-31 |
| Value | 214 | 171 | 167 | 192 | 164 | 161 | 173 | 135 |
| Percentage of AccruedLiabilitiesAndOtherCurrentLiabilitiesCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-10-02 |
| Value | 17000.0 |
| Percentage of BusinessCombinationFutureInvestmentInAcquisitionExtensionSquareFootOfGamingFloor | 100.0 |
| Period End | 2021-12-31 |
| Value | 155000.0 |
| Percentage of BusinessCombinationFutureInvestmentInAcquisitionExtensionSquareFootOfGamingFloor | 0.0 |
| Period End | 2020-12-31 |
| Value | 17000.0 |
| Percentage of BusinessCombinationFutureInvestmentInAcquisitionExtensionSquareFootOfGamingFloor | 0.0 |
| Period End | 2021-12-31 |
| Value | 155000.0 |
| Percentage of BusinessCombinationFutureInvestmentInAcquisitionExtensionSquareFootOfGamingFloor | 0.0 |
| Period End | 2021-03-17 |
| Value | 3.25 |
| Percentage of DebtInstrumentUnamortizedPremiumPercentage | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 2800000.0 | 2700000.0 | 2200000.0 | 2100000.0 | 3700000.0 | 1869000.0 | 3822000.0 | 3574000.0 | 4239000.0 | 5294000.0 |
| Percentage of DeferredTaxAssetDeferredLiabilities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 7700000.0 | 6800000.0 |
| Percentage of DeferredTaxAssetLeaseLiabilities | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 7400000.0 | 6800000.0 |
| Percentage of DeferredTaxLiabilitiesRightOfUseAssets | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 5300000.0 |
| Percentage of DeferredTaxLiabilityCARESAct | 100.0 |
| Period End | 2020-12-31 |
| Value | 2700000.0 |
| Percentage of EmployeeRetentionTaxCreditReceivedCARESAct | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2012-12-31 |
| Value | 270 | 271 | 273 | 256 | 244 | 243 | 243 | 95 | 98 | 231 | 233 | 234 | 198 | 112 | 114 | 117 | 119 | 122 | 125 | 128 | 130 | 133 | 146 | 148 | 151 | 3.662 |
| Percentage of EquityMethodInvestmentPropertyPlantEquipment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2016-12-31 |
| Value | 783 | 790 | 775 | 745 | 740 | 735 | 752 | 0.0 | 1.6 | 104 | 114 | 110 | 69 |
| Percentage of EquityMethodInvestmentSummarizedFinancialInformationLongtermDebt | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 2300000.0 |
| Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonthsthroughYearFive | 100.0 |
| Period End | 2020-12-31 |
| Value | 3050.0 |
| Percentage of HistoricalRacingMachines | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 |
| Value | 671 | 672 | 530 | 1076 | 1077 | 1071 | 384 |
| Percentage of LongTermDebtExcludingCurrentMaturitiesAndNotesPayable | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2014-12-31 |
| Value | 3200000.0 | 4000000.0 | 4700000.0 | 5100000.0 | 500000.0 | 500000.0 | 500000.0 | 500000.0 | 600000.0 | 600000.0 | 600000.0 | 638000.0 | 787000.0 |
| Percentage of LongtermDebtCurrentMaturitiesAndLoanOriginationFees | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 |
| Value | 1633 | 1488 | 892 | 1138 | 913 | 772 | 759 |
| Percentage of LongtermDebtExcludingCurrentMaturitiesGross | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 |
| Value | 530 | 384 | 387 | 632 | 312 | 171 | 458 |
| Percentage of LongtermDebtExcludingCurrentMaturitiesandNotesPayable | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 1082 | 937 |
| Percentage of PropertyPlantAndEquipmentNetAndOperatingLeaseRightOfUseAsset | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2018-12-31 |
| Value | 35 | 14 | 18 | 20 | 18 | 15 | 19 | 15 |
| Percentage of PursesPayableCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-02-01 |
| Value | 193.94 |
| Percentage of StockRepurchasedDuringPeriodPricePerShare | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 |
| Value | 70 | 57 | 47 |
| Percentage of AccountsPayableTradeCurrent | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 41 | 41 | 32 | 53 | 84 | 71 | 80 | 50 | 49 | 52 |
| Percentage of AccountsReceivableGrossCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 8.2 | 8.5 | 5.2 | 4.9 | 5.0 | 6.069 | 4.992 | 5.603 | 3.198 | 13 |
| Percentage of AccountsReceivableGrossCurrent | 19.8 | 20.4 | 15.9 | 9.2 | 5.9 | 8.5 | 6.2 | 11.0 | 6.5 | 25.7 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 26 | 20 | 19 | 20 | 21 | 14 | 17 | 19 | 18 | 11 |
| Percentage of AccountsReceivableGrossCurrent | 64.5 | 50.1 | 60.7 | 38.5 | 24.9 | 20.6 | 21.6 | 38.8 | 37.1 | 22.4 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 6.5 | 12 | 6.0 | 5.5 | 31 | 33 | 46 | 16 | 19 | 18 |
| Percentage of AccountsReceivableGrossCurrent | 15.7 | 29.5 | 18.3 | 10.3 | 37.2 | 46.2 | 58.6 | 31.7 | 39.3 | 36.1 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2013-12-31 |
| Value | -900000.0 | -900000.0 | -900000.0 | -900000.0 | -900000.0 | -900000.0 | -900000.0 | -900000.0 | -900000.0 | -900000.0 | -900000.0 | -900000.0 | -900000.0 | -900000.0 | -1300000.0 | -1000000.0 | -1500000.0 | -1300000.0 | -1200000.0 | -400000.0 | -400000.0 | -600000.0 | -588000.0 | -482000.0 | -540000.0 | -512000.0 | -125000.0 | 0 |
| Percentage of AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 4900000.0 | 4400000.0 | 4000000.0 | 3600000.0 | 3900000.0 | 3800000.0 | 3800000.0 | 3500000.0 | 3500000.0 | 3400000.0 | 3800000.0 | 3761000.0 | 3957000.0 | 3839000.0 | 4206000.0 | 4246000.0 | 5020000.0 | 4705000.0 | 4487000.0 | 4338000.0 | 1635000.0 | 1588000.0 | 1780000.0 | 1885000.0 | 2432000.0 | 2080000.0 | 2306000.0 | 2408000.0 | 4164000.0 | 4032000.0 | 4098000.0 |
| Percentage of AllowanceForDoubtfulAccountsReceivableCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 |
| Value | 10 | 9.8 | 9.7 | 7.2 | 12 | 8.9 | 7.4 | 7.4 |
| Percentage of CapitalizedComputerSoftwareNet | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-01-01 |
| Value | 41 | 74 | 53 | 60 | 108 | 119 | 63 | 35 | 35 | 121 | 69 | 37 | 78 |
| Percentage of ContractWithCustomerLiability | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 |
| Value | 17 | 16 | 21 |
| Percentage of ContractWithCustomerLiabilityNoncurrent | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 |
| Value | 1637 | 1492 | 896 | 1142 | 927 | 788 | 770 |
| Percentage of DebtInstrumentCarryingAmount | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-03-17 | 2017-12-27 |
| Value | 200 | 500 |
| Percentage of DebtInstrumentFaceAmount | 100.0 | 100.0 |
| Period End | 2021-03-17 |
| Value | 200 |
| Percentage of DebtInstrumentFaceAmount | 100.0 |
| Period End | 2021-03-17 |
| Value | 300 |
| Percentage of DebtInstrumentFaceAmount | 150.0 |
| Period End | 2028-12-31 |
| Value | 700 |
| Percentage of DebtInstrumentFaceAmount | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 |
| Value | 299 | 300 |
| Percentage of DebtInstrumentFairValue | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 |
| Value | 386 | 387 | 388 |
| Percentage of DebtInstrumentFairValue | 129.0 | 129.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 388 | 389 | 390 | 392 |
| Percentage of DebtInstrumentFairValue | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 |
| Value | 295 | 295 |
| Percentage of DebtInstrumentFairValue | 98.6 | 98.6 |
| Period End | 2021-06-30 | 2021-03-31 |
| Value | 299 | 300 |
| Percentage of DebtInstrumentFairValue | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 |
| Value | 383 | 384 | 384 |
| Percentage of DebtInstrumentFairValue | 128.0 | 128.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 |
| Value | 386 | 387 | 388 |
| Percentage of DebtInstrumentFairValue | 129.0 | 129.0 | 0.0 |
| Period End | 2020-12-31 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2017-12-31 |
| Value | 388 | 387 | 388 | 388 | 389 | 390 | 391 | 394 |
| Percentage of DebtInstrumentFairValue | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 385 | 386 | 388 |
| Percentage of DebtInstrumentFairValue | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 388 | 389 | 390 | 392 |
| Percentage of DebtInstrumentFairValue | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | 694 | 694 | 688 |
| Percentage of DebtInstrumentFairValue | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | 694 | 694 | 688 |
| Percentage of DebtInstrumentFairValue | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | 694 | 694 | 688 |
| Percentage of DebtInstrumentFairValue | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 |
| Value | 149 |
| Percentage of DebtInstrumentFairValue | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 624 | 625 | 635 | 624 | 584 | 558 | 636 | 635 | 627 | 607 |
| Percentage of DebtInstrumentFairValue | 208.6 | 208.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2017-12-31 |
| Value | 722 | 724 | 526 | 501 | 480 | 435 | 515 | 511 | 502 | 476 | 452 | 496 |
| Percentage of DebtInstrumentFairValue | 241.5 | 241.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 |
| Value | 149 |
| Percentage of DebtInstrumentFairValue | 0.0 |
| Period End | 2020-12-31 |
| Value | 149 |
| Percentage of DebtInstrumentFairValue | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 593 | 593 | 600 | 592 | 592 | 592 | 592 | 591 | 591 | 591 |
| Percentage of DebtInstrumentFairValue | 198.4 | 197.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 624 | 625 | 635 | 624 | 584 | 558 | 636 | 635 | 627 | 607 |
| Percentage of DebtInstrumentFairValue | 208.6 | 208.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2017-12-31 |
| Value | 698 | 698 | 500 | 494 | 494 | 494 | 493 | 493 | 493 | 493 | 493 | 0.0 |
| Percentage of DebtInstrumentFairValue | 233.2 | 232.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2017-12-31 |
| Value | 722 | 724 | 526 | 501 | 480 | 435 | 515 | 511 | 502 | 476 | 452 | 496 |
| Percentage of DebtInstrumentFairValue | 241.5 | 241.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-12-31 |
| Value | 2032 | 1699 |
| Percentage of DebtInstrumentFairValue | 679.1 | 0.0 |
| Period End | 2021-06-30 | 2020-12-31 |
| Value | 1970 | 1622 |
| Percentage of DebtInstrumentFairValue | 658.2 | 0.0 |
| Period End | 2021-06-30 | 2020-12-31 |
| Value | 2032 | 1699 |
| Percentage of DebtInstrumentFairValue | 679.1 | 0.0 |
| Period End | 2020-12-31 | 2014-12-31 | 2013-12-31 |
| Value | 1637 | 770 | 369 |
| Percentage of DebtLongtermAndShorttermCombinedAmount | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 800000.0 |
| Percentage of DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible | 100.0 |
| Period End | 2021-03-17 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 3400000.0 | 1100000.0 | 2300000.0 | 100000.0 | 200000.0 |
| Percentage of DeferredFinanceCostsGross | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 274 | 237 | 96 | 59 | 186 | 190 | 200 | 65 | 60 | 55 |
| Percentage of DeferredIncomeTaxLiabilities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 23 | 52 | 32 | 42 | 89 | 98 | 42 | 14 | 15 | 96 | 47 | 12 | 13 | 91 | 70 | 12 | 11 | 85 | 64 | 11 | 12 | 81 | 46 | 9.719 | 10 | 75 | 51 | 12 | 11 | 70 | 49 | 12 | 11 | 64 | 43 | 12 | 10 | 56 | 33 | 18 | 14 | 24 |
| Percentage of DeferredRevenueCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 14 | 18 | 17 | 14 | 15 | 16 | 16 | 17 | 17 | 21 | 21 | 21 | 21 | 25 | 29 | 23 | 20 | 24 | 24 | 21 | 21 | 16 | 16 | 15 | 13 | 17 | 16 | 15 | 14 | 17 | 16 | 16 | 15 | 18 | 17 | 17 | 16 | 18 | 17 | 17 | 15 | 15 |
| Percentage of DeferredRevenueNoncurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 29 |
| Percentage of DeferredTaxAssetsCapitalLossCarryforwards | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 5.5 | 4.8 | 5.6 | 4.7 | 6.3 | 14 | 0.752 | 6.328 | 8.396 | 7.656 |
| Percentage of DeferredTaxAssetsDeferredIncome | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 62 | 24 | 18 | 19 | 33 | 63 | 69 | 44 | 45 | 50 |
| Percentage of DeferredTaxAssetsGross | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 9.3 | 3.4 | 3.7 | 5.1 | 9.4 | 11 | 32 | 19 | 20 | 25 |
| Percentage of DeferredTaxAssetsOperatingLossCarryforwards | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 6.7 | 5.9 | 5.8 | 6.5 | 13 | 34 | 31 | 14 | 12 | 11 |
| Percentage of DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 1200000.0 | 1000000.0 | 900000.0 | 800000.0 | 1200000.0 | 1251000.0 | 1323000.0 | 1295000.0 | 281000.0 | 412000.0 |
| Percentage of DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 65 | 60 | 49 | 29 | 135 | 142 | 151 | 22 | 18 | 17 |
| Percentage of DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 |
| Value | 121 | 114 | 6.9 | 6.8 | 11 |
| Percentage of DeferredTaxLiabilitiesInvestmentInNoncontrolledAffiliates | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 2.2 | 2.0 | 1.3 | 1.2 | 16 | 15 | 11 | 2.246 | 1.874 | 0.0 |
| Percentage of DeferredTaxLiabilitiesOther | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 77 | 53 | 38 | 22 | 35 | 31 | 37 | 40 | 40 | 38 |
| Percentage of DeferredTaxLiabilitiesPropertyPlantAndEquipment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 |
| Value | 25 | 23 | 22 | 23 | 21 | 19 | 17 | 15 |
| Percentage of DividendsPayableCurrentAndNoncurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2018-12-31 |
| Value | 21 | 14 | 19 | 21 | 8.5 | 11 | 29 | 24 |
| Percentage of EmployeeRelatedLiabilitiesCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 |
| Value | 24 | 27 | 29 | 8.4 |
| Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 |
| Value | 14 | 16 | 17 | 3.4 |
| Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions | 57.0 | 60.1 | 61.0 | 40.5 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 |
| Value | 0.8 | 3.3 | 2.9 | 3.0 |
| Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions | 3.2 | 11.9 | 9.9 | 35.7 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 |
| Value | 9.9 | 7.8 | 8.5 | 2.0 |
| Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions | 39.8 | 28.1 | 29.1 | 23.8 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 | 2019-09-30 | 2019-03-05 | 2019-03-04 |
| Value | 833 | 833 | 834 | 840 | 835 | 841 |
| Percentage of EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquity | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 |
| Value | 832 | 833 |
| Percentage of EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquity | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 |
| Value | 50.0 | 50.0 | 50.0 | 0.5 | 0.5 | 0.5 |
| Percentage of EquityMethodInvestmentOwnershipPercentage | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2017-12-31 | 2016-12-31 | 2012-12-31 |
| Value | 50.0 | 50.0 | 50.0 | 50.0 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 |
| Percentage of EquityMethodInvestmentOwnershipPercentage | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2019-03-06 | 2019-03-05 | 2019-03-04 | 2018-10-31 |
| Value | 61.3 | 61.3 | 0.613 | 0.613 | 0.613 | 0.613 | 0.613 | 0.613 | 0.613 | 0.42 | 0.42 | 1.0 |
| Percentage of EquityMethodInvestmentOwnershipPercentage | 122.6 | 0.0 | 0.0 | 0.0 | 122.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2012-12-31 |
| Value | 668 | 615 | 645 | 560 | 539 | 537 | 546 | 226 | 226 | 543 | 545 | 535 | 401 | 234 | 236 | 240 | 250 | 250 | 254 | 255 | 260 | 239 | 244 | 250 | 250 | 80 |
| Percentage of EquityMethodInvestmentSummarizedFinancialInformationAssets | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2012-12-31 |
| Value | 151 | 98 | 126 | 64 | 59 | 58 | 67 | 24 | 21 | 71 | 74 | 64 | 38 | 15 | 14 | 16 | 24 | 23 | 23 | 22 | 24 | 25 | 17 | 21 | 18 | 1.982 |
| Percentage of EquityMethodInvestmentSummarizedFinancialInformationCurrentAssets | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2012-12-31 |
| Value | 119 | 91 | 112 | 73 | 75 | 89 | 87 | 21 | 19 | 96 | 101 | 100 | 77 | 11 | 10 | 13 | 21 | 17 | 17 | 15 | 16 | 14 | 21 | 31 | 46 | 1.986 |
| Percentage of EquityMethodInvestmentSummarizedFinancialInformationCurrentLiabilities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2012-12-31 |
| Value | -277.5 | -309.7 | -284.4 | -278.7 | -301.7 | -307.1 | -300.9 | 205 | 205 | 340 | 329 | 325 | 255 | 199 | 199 | 199 | 200 | 202 | 204 | 207 | 209 | 188 | 184 | 179 | 162 | 28 |
| Percentage of EquityMethodInvestmentSummarizedFinancialInformationEquity | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2012-12-31 |
| Value | 668 | 615 | 645 | 560 | 539 | 537 | 546 | 226 | 226 | 543 | 545 | 535 | 401 | 234 | 236 | 240 | 250 | 250 | 254 | 255 | 260 | 239 | 244 | 250 | 250 | 80 |
| Percentage of EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2012-12-31 |
| Value | 246 | 246 | 246 | 240 | 236 | 235 | 235 | 106 | 107 | 241 | 237 | 236 | 363 | 107 | 107 | 107 | 106 | 105 | 105 | 105 | 105 | 80 | 80 | 80 | 80 | 74 |
| Percentage of EquityMethodInvestmentSummarizedFinancialInformationNoncurrentAssets | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2012-12-31 |
| Value | 42 | 43 | 41 | 20 | 25 | 20 | 7.5 | 0.0 | 0.1 | 1.2 | 0.0 | 0.1 | 69 | 15 | 17 | 18 | 20 | 22 | 23 | 25 | 26 | 28 | 29 | 39 | 40 | 50 |
| Percentage of EquityMethodInvestmentSummarizedFinancialInformationNoncurrentLiabilities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2019-12-31 | 2012-12-31 | 2012-12-21 |
| Value | 108 | 109 | 110 | 110 | 60 | 60 |
| Percentage of EquityMethodInvestments | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 519 | 522 |
| Percentage of EquityMethodInvestments | 471.4 | 471.2 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 |
| Value | 535 | 523 | 519 |
| Percentage of EquityMethodInvestments | 494.2 | 478.6 | 471.4 |
| Period End | 2020-12-31 |
| Value | 6200000.0 |
| Percentage of FinanceLeaseLiability | 100.0 |
| Period End | 2020-12-31 |
| Value | 200000.0 |
| Percentage of FinanceLeaseLiabilityCurrent | 100.0 |
| Period End | 2020-12-31 |
| Value | 6000000.0 |
| Percentage of FinanceLeaseLiabilityNoncurrent | 100.0 |
| Period End | 2020-12-31 |
| Value | 8000000.0 |
| Percentage of FinanceLeaseLiabilityPaymentsDue | 100.0 |
| Period End | 2020-12-31 |
| Value | 6000000.0 |
| Percentage of FinanceLeaseLiabilityPaymentsDueAfterYearFive | 100.0 |
| Period End | 2020-12-31 |
| Value | 400000.0 |
| Percentage of FinanceLeaseLiabilityPaymentsDueNextTwelveMonths | 100.0 |
| Period End | 2020-12-31 |
| Value | 400000.0 |
| Percentage of FinanceLeaseLiabilityPaymentsDueYearFive | 100.0 |
| Period End | 2020-12-31 |
| Value | 400000.0 |
| Percentage of FinanceLeaseLiabilityPaymentsDueYearFour | 100.0 |
| Period End | 2020-12-31 |
| Value | 400000.0 |
| Percentage of FinanceLeaseLiabilityPaymentsDueYearThree | 100.0 |
| Period End | 2020-12-31 |
| Value | 400000.0 |
| Percentage of FinanceLeaseLiabilityPaymentsDueYearTwo | 100.0 |
| Period End | 2020-12-31 |
| Value | 1800000.0 |
| Percentage of FinanceLeaseLiabilityUndiscountedExcessAmount | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 2.9 | 3.9 |
| Percentage of FinanceLeaseWeightedAverageDiscountRatePercent | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 |
| Value | 19 | 17 | 16 | 15 | 16 | 16 | 15 | 13 | 16 | 15 | 14 | 23 | 23 | 22 | 20 | 113 | 103 | 110 | 100 | 118 | 105 | 98 | 86 | 73 | 68 | 61 | 47 | 42 | 41 | 39 | 36 | 36 | 33 | 32 | 29 | 26 | 26 | 20 |
| Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 8.8 | 8.1 | 7.5 | 6.8 | 6.2 | 5.554 | 4.907 | 4.26 | 3.613 | 2.966 |
| Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization | 53.0 | 54.0 | 53.2 | 33.0 | 6.2 | 6.4 | 10.4 | 11.8 | 12.2 | 14.3 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 2.2 | 1.6 | 2.5 | 10 | 33 | 47 | 39 | 30 | 24 | 16 |
| Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization | 13.3 | 10.7 | 17.7 | 51.5 | 33.3 | 54.2 | 83.4 | 84.2 | 83.1 | 79.1 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 |
| Value | 2.1 | 2.0 | 1.8 | 1.7 |
| Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization | 12.7 | 13.3 | 12.8 | 8.3 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 3.5 | 3.3 | 2.3 | 1.5 | 1.0 | 0.356 | 0.326 | 0.297 | 0.267 | 0.237 |
| Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization | 21.1 | 22.0 | 16.3 | 7.3 | 1.0 | 0.4 | 0.7 | 0.8 | 0.9 | 1.1 |
| Period End | 2020-12-31 |
| Value | 3600000.0 |
| Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths | 100.0 |
| Period End | 2020-12-31 |
| Value | 1200000.0 |
| Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearFive | 100.0 |
| Period End | 2020-12-31 |
| Value | 1900000.0 |
| Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearFour | 100.0 |
| Period End | 2020-12-31 |
| Value | 2400000.0 |
| Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearThree | 100.0 |
| Period End | 2020-12-31 |
| Value | 2500000.0 |
| Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 |
| Value | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 33 | 32 | 32 | 42 | 40 | 39 | 39 | 180 | 179 | 187 | 187 | 218 | 218 | 223 | 224 | 224 | 231 | 238 | 238 | 76 | 76 | 76 | 76 | 79 | 75 | 75 | 75 | 64 | 64 | 64 |
| Percentage of FiniteLivedIntangibleAssetsGross | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 4.7 | 4.7 | 6.4 | 16 | 43 | 75 | 89 | 56 | 57 | 47 |
| Percentage of FiniteLivedIntangibleAssetsGross | 15.1 | 15.0 | 19.9 | 42.0 | 22.9 | 33.4 | 37.3 | 74.4 | 77.0 | 73.2 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 |
| Value | 5.1 | 5.1 | 5.2 | 5.0 |
| Percentage of FiniteLivedIntangibleAssetsGross | 16.3 | 16.3 | 16.2 | 12.6 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 10 | 10 | 9.5 | 7.1 | 3.7 | 3.699 | 3.719 | 3.719 | 4.079 | 4.059 |
| Percentage of FiniteLivedIntangibleAssetsGross | 33.3 | 33.5 | 29.6 | 17.8 | 2.0 | 1.6 | 1.6 | 4.9 | 5.4 | 6.3 |
| Period End | 2020-12-31 |
| Value | 200000.0 |
| Percentage of IncomeTaxExaminationPenaltiesAndInterestAccrued | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 39 | 69 | 49 | 40 | 36 | 25 | 14 | 1.4 | 0.0 | 16 | 17 | 0.0 | 0.0 | 0.0 | 35 | 0.0 | 0.0 | 1.0 | 7.6 | 0.0 | 0.0 | 6.6 | 1.037 | 0.0 | 0.0 | 14 | 29 | 0.0 | 0.0 | 8.195 | 12 | 0.0 | 0.0 | 3.375 | 2.915 | 0.0 | 0.0 | 3.569 | 3.679 | 0.0 | 0.0 | 11 |
| Percentage of IncomeTaxesReceivable | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2018-12-31 |
| Value | 24 | 23 | 19 | 21 | 19 | 22 | 19 | 11 |
| Percentage of InterestPayableCurrentAndNoncurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 5500000.0 |
| Percentage of LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2016-12-31 |
| Value | 124 | 124 | 124 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 188 | 207 |
| Percentage of LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 100.0 | 100.0 |
| Period End | 2021-03-17 |
| Value | 300 |
| Percentage of LineOfCreditFacilityMaximumBorrowingCapacity | 100.0 |
| Period End | 2020-12-31 |
| Value | 1100 |
| Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive | 100.0 |
| Period End | 2020-12-31 |
| Value | 4000000.0 |
| Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths | 100.0 |
| Period End | 2020-12-31 |
| Value | 525 |
| Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour | 100.0 |
| Period End | 2020-12-31 |
| Value | 4000000.0 |
| Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree | 100.0 |
| Period End | 2020-12-31 |
| Value | 4000000.0 |
| Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2013-12-31 |
| Value | 1291 | 1291 | 1087 | 1087 | 1086 | 1086 | 1085 | 1085 | 1084 | 1084 | 493 | 492 | 492 | 492 | 492 | 595 | 595 | 595 | 594 | 594 | 594 | 593 | 593 | 300 | 300 | 300 | 300 | 300 |
| Percentage of NotesPayableToBankNoncurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 3.8 | 3.9 |
| Percentage of OperatingLeaseWeightedAverageDiscountRatePercent | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 |
| Value | 3.2 | 3.2 | 4.6 |
| Percentage of OperatingLossCarryforwards | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 |
| Value | 7.3 | 0.7 |