| 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:CommonStockValue | ██▆▆▆▆▆▆▆▃▃▃▃▃▃▃▃▁▁▁▁▁▁▁▃▃▃▃▃▆▆▆▆▆▆▆▆▃ | 0.048 | 0.048 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | 0.045 | 0.045 | 0.045 | 0.045 | 0.045 | 0.045 | 0.045 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.046 | NA | 0.046 | 0.046 | 0.046 | NA | NA | 0.046 | NA | NA | NA |
| us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding | ▁█ | 46.229603 | 46.507258 | NA | 45.815718 | 46.686665 | 46.391066 | 46.14597 | 46.019691 | 45.912291 | 45.644236 | 45.803418 | 45.699635 | 45.536473 | 45.294697 | 44.844469 | 45.118607 | 44.988655 | 44.917014 | 44.558089 | 44.776918 | 44.705037 | 44.571937 | 44.558089 | 44.702127 | 45.054507 | 45.15825 | 45.229125 | 45.629079 | 46.294966 | 46.90736 | 48.80056 | 46.823167 | 46.769184 | 46.435677 | 45.492847 | 45.377732 | 45.313804 | 45.241418 | 45.241418 | 45.58258 | 45.559972 | 45.548725 | 44.731858 | 44.731858 | 45.005387 | 44.58523 | 44.525633 | 44.464821 |
| us-gaap:WeightedAverageNumberOfSharesOutstandingBasic | █▁ | 46.229603 | 46.067096 | NA | 45.815718 | 45.75488 | 45.658565 | 45.553727 | 45.438656 | 45.354327 | 45.223157 | 45.284481 | 45.10583 | 45.016767 | 44.923973 | 44.844469 | 44.767163 | 44.717372 | 44.649645 | 44.323131 | 44.574583 | 44.491899 | 44.40264 | 44.323131 | 44.474724 | 44.774831 | 45.15825 | 45.229125 | 45.629079 | 45.897449 | 46.409735 | 46.302926 | 46.171194 | 46.040692 | 45.537607 | 45.492847 | 45.377732 | 45.313804 | 45.241418 | 45.241418 | 45.044733 | 45.080859 | 45.021507 | 44.731858 | 44.731858 | 44.646381 | 44.58523 | 44.525633 | 44.464821 |
| us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecurities us-gaap:EmployeeStockOption | ▁█ | 0.036063 | 0.077832 | NA | NA | 0.018496 | 0.09307 | NA | 0.037606 | 0.036381 | 0.069208 | NA | 0.030836 | 0.043308 | 0.077284 | NA | 0.054908 | 0.062175 | 0.048534 | NA | 0.075687 | 0.064349 | 0.111897 | NA | 0.13622 | 0.120533 | 0.098102 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecurities us-gaap:RestrictedStock | ▁█ | 0.028019 | 0.39241 | NA | NA | NA | 0.011884 | NA | NA | 0.037494 | NA | NA | NA | NA | 0.078087 | NA | 0.000195 | 0.138909 | NA | NA | NA | NA | NA | NA | 0.617243 | 0.369243 | 0.00336 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 0.7 | NA | NA | NA | 0.2 | 1.2 | NA | NA | NA | NA | NA |
| us-gaap:EarningsPerShareBasic | ▄ | -0.05 | NA | -0.14 | -0.11 | 0.19 | NA | 0.15999999999999992 | 0.3 | 0.16 | 0.2 | 0.16 | 0.18 | 0.15 | 0.15 | -0.14 | 0.08000000000000002 | 0.1 | NA | NA | NA | NA | NA | NA | NA | NA | NA | -0.01 | 0.0 | 0.03 | 0.0 | 1.14 | 0.05 | 0.03 | 0.01 | NA | NA | NA | NA | NA | NA | NA | 0.05 | NA | NA | NA | NA | -0.02 | NA |
| us-gaap:EarningsPerShareBasic us-gaap:StatementScenario ccoi:Unaudited | NA | NA | -0.14 | -0.11 | 0.19 | 0.2 | 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 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:EarningsPerShareDiluted | ▄ | -0.05 | NA | -0.15000000000000002 | -0.11 | 180.0 | NA | 0.16000000000000003 | 0.3 | 0.16 | NA | 0.16 | 0.18 | 0.14 | NA | -0.14 | 0.08000000000000002 | 0.1 | NA | NA | NA | NA | NA | 0.06 | 0.07 | 0.02 | -0.04 | -0.01 | 0.0 | 0.03 | 0.0 | 1.1 | 0.05 | 0.03 | 0.01 | NA | NA | NA | NA | NA | NA | NA | 0.05 | NA | NA | NA | NA | -0.02 | NA |
| us-gaap:EarningsPerShareDiluted us-gaap:StatementScenario ccoi:Unaudited | NA | NA | -0.14 | -0.11 | 0.18 | 0.2 | 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 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:EarningsPerShareBasicAndDiluted | NA | 0.41 | NA | NA | NA | 0.2 | 0.16 | 0.3 | 0.16 | 0.2 | 0.16 | 0.18 | 0.15 | 0.15 | -0.14 | 0.08 | 0.1 | 0.09 | 0.06 | 0.08 | 0.09 | 0.08 | 0.09 | 0.07 | 0.02 | -0.04 | NA | 0.0 | 0.03 | 0.0 | NA | 0.05 | 0.03 | 0.01 | -0.01 | 0.0 | -0.04 | -0.05 | -0.05 | 0.12 | 0.01 | 0.05 | -0.01 | -0.01 | 0.06 | -0.01 | -0.02 | -0.01 |
| 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| COGS Ratio us-gaap:StatementScenario ccoi:Unaudited | NA | NA | 143.901 | 142.302 | 140.99 | 140.915 | 140.292 | 136.942 | 134.789 | 134.137 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| Operating Margin us-gaap:StatementScenario ccoi:Unaudited | NA | NA | 143.901 | 142.302 | 140.99 | 140.915 | 140.292 | 136.942 | 134.789 | 134.137 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TTM Greenblatt ROC _ _ | █▇█▇█▇█▇▆▇▆▆▆▆▆▅▅▅▄▄▅▄▄▄▃▂▃▃▄▃▃▃▃▂▂▂▂▁▁▃▂▂▁▁▁ | 28.211 | 26.291 | 27.377 | 26.036 | 27.574 | 25.85 | 28.033 | 25.799 | 22.022 | 24.4 | 22.311 | 22.255 | 21.354 | 20.637 | 20.534 | 17.72 | 19.0 | 18.666 | 16.174 | 16.063 | 17.511 | 15.675 | 16.174 | 15.519 | 10.81 | 10.487 | 13.066 | 13.614 | 14.309 | 12.907 | 12.065 | 12.577 | 11.601 | 9.905 | 9.169 | 8.032 | 7.801 | 5.968 | 5.968 | 10.899 | 9.576 | 8.671 | 7.358 | 7.358 | 5.864 | 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:AllocatedShareBasedCompensationExpense | ▇█▅▇▆▄▄▃▄▁▃▄▃▂ | 6.874 | 7.307 | 5.846 | 6.522 | 6.082 | 5.075 | 4.94 | 4.796 | 5.29 | 3.434 | 4.408 | 4.821 | 4.695 | 3.784 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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:ComprehensiveIncomeNetOfTax | ▂▄▂▂▃▃▃▃▃▃▃▃▂▃▁▃▃▃▂▂▂▃▂▂▂▁▂▁▂▂█▃▂▂▂▂▁▂ | -0.717 | 13.641 | -0.428 | 0.453 | 11.477 | 5.734 | 10.816 | 8.992 | 8.922 | 7.392 | 4.844 | 7.746 | 0.354 | 9.395 | -4.915 | 7.44 | 10.48 | 5.464 | -1.403 | 4.147 | 2.257 | 7.428 | -0.266 | 3.389 | 2.523 | -8.981 | -3.41 | -5.218 | 1.164 | -0.337 | 53.194 | 4.463 | 1.933 | -1.432 | 0.917 | 1.407 | -4.859 | -0.467 | NA | 3.286 | -3.037 | 2.96 | 2.707 | NA | NA | NA | NA | NA |
| us-gaap:CostOfGoodsAndServicesSold | ▇█▆▅▅▇▇▆▅▅▆▅▅▆▅▄▁▁ | 56.18 | 57.092 | 54.831 | 54.519 | 53.886 | 55.921 | 55.99 | 55.253 | 54.407 | 54.15 | 55.66 | 54.615 | 54.379 | 54.875 | 53.918 | 53.584 | 51.115 | 50.662 | NA | NA | NA | NA | NA | NA | 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:CostsAndExpenses | ██▇▇▇▇▇▇▇▇▇▆▆▆▆▆▅▅▅▅▅▄▄▄▄▄▃▃▂▂▂▂▂▂▁▁▁▁ | 119.668 | 120.504 | 116.53 | 115.86 | 113.621 | 115.104 | 112.508 | 111.23 | 112.952 | 110.273 | 109.832 | 108.3 | 108.299 | 108.186 | 105.009 | 105.646 | 101.8 | 100.661 | 101.47 | 97.681 | 96.296 | 94.562 | 91.028 | 90.134 | 88.708 | 88.269 | 83.683 | 82.077 | 80.314 | 80.03 | 77.792 | 75.184 | 74.202 | 74.648 | 73.443 | 71.624 | 70.016 | 70.92 | NA | 68.192 | 67.791 | 66.909 | 66.102 | NA | 63.668 | 63.034 | 61.414 | NA |
| us-gaap:GainsLossesOnExtinguishmentOfDebt | NA | -3.868 | 0.0 | 0.0 | -0.638 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | -0.587 | -10.144 | 0.0 | 0.0 | 0.0 | -10.144 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 2.739 | NA | NA | NA | NA | NA | NA | |
| us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic | ▂█▁▁▅▆▅▇▅▆▆▆▅▅▅▅▅▅▃▅▅▄▅▄▃▁▄▄▄▄▄▄▄▃ | 0.828 | 28.502 | -4.01 | -4.084 | 14.113 | 17.789 | 13.236 | 24.452 | 16.332 | 18.753 | 17.644 | 16.652 | 15.446 | 14.135 | 14.984 | 12.21 | 12.69 | 12.366 | 5.17 | 11.971 | 13.23 | 11.387 | 11.727 | 9.343 | 6.078 | -5.176 | 7.757 | 7.874 | 7.578 | 8.436 | 8.629 | 8.011 | 7.943 | 6.195 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest | ▂█▁▁▅▅▅▆▅▅▅▅▄▅▄▄▄▄▃▄▄▄▄▄▃▂▃▃▃▃▃▃▃ | -2.071 | 26.201 | -7.264 | -6.555 | 11.299 | 12.835 | 10.769 | 18.955 | 10.18 | 12.771 | 10.862 | 11.425 | 9.17 | 9.923 | 8.479 | 7.086 | 7.925 | 7.629 | 4.535 | 6.379 | 7.603 | 5.743 | 6.332 | 5.567 | 1.535 | -0.723 | 0.871 | 1.092 | 0.787 | 1.741 | 2.018 | 2.301 | 1.974 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign | ▃▄▃▄▄▂▄▂▁▂▁▂▁▃▁▂▂▂▅▂▂▂▂▃▂█▁▁▁▁▁▂▂▂ | -2.899 | -2.301 | -3.254 | -2.471 | -2.814 | -4.954 | -2.467 | -5.497 | -6.152 | -5.982 | -6.782 | -5.227 | -6.276 | -4.212 | -6.505 | -5.124 | -4.765 | -4.737 | -0.635 | -5.592 | -5.627 | -5.644 | -5.395 | -3.776 | -4.543 | 4.453 | -6.886 | -6.782 | -6.791 | -6.695 | -6.611 | -5.71 | -5.969 | -5.501 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:IncomeTaxExpenseBenefit | ▆▇▆▆▇▇▇▇▇▇▇▇▇▇█▇▇▇▆▇▇▇▇▇▆▇▇▇▆▇▁▆▆▆▇▆▇▆ | 0.422 | 7.35 | -0.644 | -1.6 | 2.735 | 3.608 | 3.303 | 5.254 | 3.044 | 3.554 | 3.762 | 3.194 | 2.618 | 3.139 | 14.706 | 3.436 | 3.608 | 3.493 | 0.643 | 2.92 | 3.379 | 2.389 | 3.852 | 2.406 | 0.695 | 0.862 | 1.223 | 1.276 | -0.421 | 1.616 | -50.581 | 0.179 | 0.367 | 0.333 | 1.05 | -0.492 | 0.752 | -0.56 | NA | -3.122 | 0.423 | 0.458 | 0.281 | NA | -0.909 | 0.087 | 0.099 | NA |
| us-gaap:InterestExpense | ▆███▇▇▇▇▆▅▆▅▄▄▄▄▄▄▃▂▂▂▂▂▂▃▄▅▆▃▃▃▂▂▁▁▁▁ | 14.236 | 15.836 | 16.005 | 15.76 | 15.499 | 15.22 | 15.21 | 15.191 | 13.595 | 13.456 | 13.509 | 12.767 | 12.373 | 12.408 | 12.222 | 12.266 | 12.09 | 11.891 | 10.603 | 9.891 | 10.243 | 10.065 | 10.28 | 10.002 | 9.692 | 11.307 | 12.189 | 12.662 | 13.79 | 11.303 | 11.144 | 10.568 | 10.216 | 9.869 | 9.321 | 9.015 | 8.988 | 8.993 | NA | 8.838 | 8.953 | 9.135 | 7.585 | NA | 4.342 | 4.1 | 4.148 | NA |
| us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic | ▁▄▁▁▃▃▃▃▃▃▃▃▃▃▁▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂█▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂ | -2.493 | 18.851 | -6.62 | -4.955 | 8.564 | 9.227 | 7.465 | 13.701 | 7.136 | 9.217 | 7.1 | 8.231 | 6.552 | 6.784 | -6.227 | 3.65 | 4.317 | 4.136 | 2.48 | 3.459 | 4.224 | 3.354 | 2.48 | 3.161 | 0.84 | -1.585 | -0.352 | -0.184 | 1.208 | 0.125 | 52.599 | 2.122 | 1.607 | 0.361 | -0.276 | -0.094 | -1.791 | -2.09 | -2.09 | 5.424 | 0.281 | 2.115 | -0.278 | -0.278 | 2.584 | -0.462 | -0.883 | -0.57 |
| us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic us-gaap:StatementEquityComponents us-gaap:RetainedEarnings | ▂█▁▁▅▅▅▇▅▅▅▅▅▅ | -2.493 | 18.851 | -6.62 | -4.955 | 8.564 | 9.227 | 7.466 | 13.701 | 7.136 | 9.217 | 7.1 | 8.231 | 6.552 | 6.784 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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 us-gaap:StatementScenario ccoi:Unaudited | NA | NA | -6.62 | -6.555 | 8.564 | 9.227 | 7.465 | 13.701 | 7.136 | 9.217 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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:OperatingIncomeLoss | █▇█▇█▇█▇▆▇▆▆▆▆▆▅▅▅▅▅▅▅▅▅▃▃▄▄▄▄▄▄▃▃▃▂▂▂▂▃▃▃▂▂▂▁▁▁ | 28.211 | 26.291 | 27.377 | 26.036 | 27.574 | 25.85 | 28.033 | 25.799 | 22.022 | 24.4 | 22.311 | 22.255 | 21.354 | 20.637 | 20.534 | 17.72 | 19.0 | 18.666 | 16.174 | 16.063 | 17.511 | 15.675 | 16.174 | 15.519 | 10.81 | 10.487 | 13.066 | 13.614 | 14.309 | 12.907 | 12.065 | 12.577 | 11.601 | 9.905 | 9.169 | 8.032 | 7.801 | 5.968 | 5.968 | 10.899 | 9.576 | 8.671 | 7.358 | 7.358 | 5.864 | 3.749 | 2.981 | 2.688 |
| us-gaap:ProfitLoss | ▂█▁▁▅▅▅▇▅▅▅▅▅▅ | -2.493 | 18.851 | -6.62 | -4.955 | 8.564 | 9.227 | 7.466 | 13.701 | 7.136 | 9.217 | 7.1 | 8.231 | 6.552 | 6.784 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 2.115 | NA | NA | NA | NA | -0.883 | NA |
| us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax | ████▇▇▇▇▇▇▇▇▆▆▆▆▆▅▄▄▄▄▄▄▄▄▄▄▄▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂▁▁▁ | 147.879 | 146.777 | 143.898 | 142.302 | 140.99 | 140.915 | 140.292 | 136.942 | 134.789 | 134.137 | 132.049 | 130.139 | 129.296 | 128.706 | 125.226 | 122.969 | 119.777 | 117.203 | 105.177 | 103.017 | 98.799 | 97.242 | 105.177 | 103.017 | 98.799 | 97.242 | 96.749 | 95.691 | 94.623 | 92.937 | 89.859 | 87.761 | 85.803 | 84.553 | 82.612 | 79.656 | 77.817 | 76.888 | 76.888 | 79.093 | 77.367 | 75.58 | 73.46 | 73.46 | 69.461 | 66.783 | 64.395 | 62.776 |
| us-gaap:SellingGeneralAndAdministrativeExpense | ██▇▇▇▇▆▆▇▆▅▅▆▅▅▅▅▅▅▄▄▄▃▄▄▄▄▄▃▃▂▂▂▂▁▁▁▂ | 41.392 | 41.442 | 39.244 | 39.722 | 39.839 | 39.675 | 36.517 | 35.971 | 38.566 | 35.86 | 33.218 | 33.409 | 33.704 | 33.523 | 31.75 | 32.915 | 31.788 | 31.461 | 31.306 | 30.05 | 29.82 | 29.532 | 27.181 | 27.318 | 28.925 | 29.677 | 27.904 | 27.353 | 26.139 | 26.285 | 22.832 | 21.719 | 21.226 | 21.465 | 19.668 | 19.473 | 19.401 | 21.343 | NA | 19.534 | 18.984 | 18.926 | 19.538 | NA | 17.794 | 17.659 | 18.091 | 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 |
|---|
| 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:Assets | █▅███▆▇▇▇▄▃▄▃▃▃▃▃▃▃▁▂▂▂▂▂▃▄▄▅▃▄▃▁▁▁▁▁▁ | 1010.747 | 852.962 | 1000.477 | 1000.914 | 1005.401 | 913.625 | 932.124 | 932.344 | 949.065 | 797.003 | 739.85 | 757.319 | 700.229 | 716.453 | 710.588 | 729.86 | 732.439 | 732.675 | 737.892 | 617.622 | 626.378 | 665.096 | 662.816 | 672.906 | 682.388 | 714.046 | 761.775 | 784.461 | 822.787 | 725.247 | 755.101 | 692.253 | 621.372 | 616.237 | 606.531 | 592.885 | 595.217 | 597.289 | NA | 597.651 | 578.104 | 587.896 | NA | NA | 376.103 | NA | NA | NA |
| us-gaap:Liabilities | █▇█▇▇▆▆▆▆▅▄▄▄▄▄▄▄▄▄▃▃▃▃▃▃▃▃▃▃▂▂▂▁▁▁▁▁▁ | 1346.888 | 1160.521 | 1293.643 | 1261.605 | 1240.951 | 1135.85 | 1135.803 | 1122.845 | 1125.655 | 961.234 | 888.852 | 883.163 | 814.865 | 813.508 | 813.132 | 809.983 | 803.64 | 796.287 | 791.146 | 658.108 | 655.767 | 683.478 | 675.087 | 671.804 | 660.199 | 659.794 | 677.981 | 675.797 | 682.165 | 562.247 | 561.609 | 537.218 | 466.834 | 460.376 | 446.752 | 431.902 | 434.068 | 432.302 | NA | 433.65 | 419.465 | 425.642 | NA | NA | 224.302 | NA | NA | NA |
| us-gaap:LiabilitiesAndStockholdersEquity | █▅███▆▇▇▇▄▃▄▃▃▃▃▃▃▃▁▂▂▂▂▂▃▄▄▅▃▄▃▁▁▁▁▁▁ | 1010.747 | 852.962 | 1000.477 | 1000.914 | 1005.401 | 913.625 | 932.124 | 932.344 | 949.065 | 797.003 | 739.85 | 757.319 | 700.229 | 716.453 | 710.588 | 729.86 | 732.439 | 732.675 | 737.892 | 617.622 | 626.378 | 665.096 | 662.816 | 672.906 | 682.388 | 714.046 | 761.775 | 784.461 | 822.787 | 725.247 | 755.101 | 692.253 | 621.372 | 616.237 | 606.531 | 592.885 | 595.217 | 597.289 | NA | 597.651 | 578.104 | 587.896 | NA | NA | 376.103 | NA | NA | NA |
| us-gaap:StockholdersEquity | ▁▁▂▂▂▃▃▃▃▃▃▄▄▄▄▄▅▅▅▅▅▅▅▅▆▆▇▇▇██▇▇█████ | -336.141 | -307.559 | -293.166 | -260.691 | -235.55 | -222.225 | -203.679 | -190.501 | -176.59 | -164.231 | -149.002 | -125.844 | -114.636 | -97.055 | -102.544 | -80.123 | -71.201 | -63.612 | -53.254 | -40.486 | -29.389 | -18.382 | -12.271 | 1.102 | 22.189 | 54.252 | 83.794 | 108.664 | 140.622 | 163.0 | 193.492 | 155.035 | 154.538 | 155.861 | 159.779 | 160.983 | 161.149 | 164.987 | NA | 164.001 | 158.639 | NA | NA | NA | 151.801 | NA | NA | NA |
| us-gaap:StockholdersEquity us-gaap:StatementEquityComponents us-gaap:AccumulatedTranslationAdjustment | ▆▅█▅▂▁▃▁▃▂▃▄▅█▆ | -4.74 | -6.516 | -1.306 | -7.498 | -12.906 | -15.819 | -12.326 | -15.676 | -10.967 | -12.753 | -10.928 | -8.672 | -8.187 | -1.989 | -4.6 | NA | NA | NA | -17.193 | NA | NA | NA | -14.693 | NA | NA | NA | -6.462 | NA | NA | NA | 2.136 | NA | NA | NA | 0.667 | NA | NA | NA | NA | -0.582 | NA | NA | NA | NA | 1.044 | NA | NA | NA |
| us-gaap:StockholdersEquity us-gaap:StatementEquityComponents us-gaap:AdditionalPaidInCapital | █▇▆▆▆▅▄▄▃▃▂▂▂▁▁ | 533.049 | 523.913 | 515.867 | 513.454 | 506.391 | 499.455 | 493.178 | 487.396 | 481.734 | 475.275 | 471.331 | 472.817 | 467.007 | 461.154 | 456.696 | NA | NA | NA | 442.799 | NA | NA | NA | 434.161 | NA | NA | NA | 460.576 | NA | NA | NA | 508.256 | NA | NA | NA | 497.349 | NA | NA | NA | NA | 489.021 | NA | NA | NA | NA | 482.737 | NA | NA | NA |
| us-gaap:StockholdersEquity us-gaap:StatementEquityComponents us-gaap:CommonStock | ██▄▄▄▄▄▄▄▁▁▁▁▁▁ | 0.048 | 0.048 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | NA | NA | NA | 0.045 | NA | NA | NA | 0.045 | NA | NA | NA | 0.046 | NA | NA | NA | 0.047 | NA | NA | NA | 0.047 | NA | NA | NA | NA | 0.046 | NA | NA | NA | NA | 0.046 | NA | NA | NA |
| us-gaap:StockholdersEquity us-gaap:StatementEquityComponents us-gaap:RetainedEarnings | ▁▂▂▃▄▅▅▆▆▆▇▇███ | -864.498 | -825.004 | -807.774 | -766.694 | -729.082 | -705.908 | -684.578 | -662.268 | -647.404 | -626.799 | -609.451 | -590.035 | -573.502 | -556.266 | -554.686 | NA | NA | NA | -478.905 | NA | NA | NA | -431.784 | NA | NA | NA | -370.366 | NA | NA | NA | -316.947 | NA | NA | NA | -338.284 | NA | NA | NA | NA | -324.484 | NA | NA | NA | NA | -332.026 | 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:AssetsCurrent | ▇▄▇▇█▇▇▇█▄▅▅▃▃▃▄▄▄▄▁▁▂▂▂▃▄▄▅▆▄▅▄▃▃▃▃▃▃ | 454.555 | 316.27 | 456.337 | 475.353 | 497.116 | 456.562 | 475.728 | 474.373 | 485.993 | 333.85 | 350.337 | 358.507 | 296.736 | 307.549 | 306.118 | 310.31 | 313.152 | 317.838 | 327.623 | 202.28 | 208.047 | 247.393 | 251.339 | 260.036 | 276.527 | 311.969 | 339.641 | 364.254 | 405.821 | 320.654 | 354.271 | 346.321 | 278.942 | 274.202 | 281.253 | 271.069 | 274.731 | 269.527 | NA | 273.287 | 258.688 | 264.733 | NA | NA | 88.639 | NA | NA | NA |
| us-gaap:CashAndCashEquivalentsAtCarryingValue | ▇▃▇▇█▇█▇█▄▄▅▃▃▄▄▄▄▄▁▁▂▂▃▃▄▅▅▆▄▅▅▃▃▄▃▃▃ | 373.963 | 237.98 | 371.301 | 393.293 | 417.026 | 375.116 | 399.422 | 396.271 | 409.279 | 259.138 | 276.093 | 284.558 | 224.282 | 236.026 | 247.011 | 250.765 | 256.492 | 263.196 | 274.319 | 148.151 | 154.967 | 196.05 | 203.591 | 207.29 | 224.494 | 260.05 | 287.79 | 311.779 | 349.835 | 263.747 | 304.866 | 304.775 | 237.335 | 234.96 | 247.285 | 232.064 | 237.227 | 232.294 | NA | 238.207 | 224.051 | 227.246 | 225.342 | NA | 56.283 | 47.835 | 52.435 | NA |
| us-gaap:AccountsReceivableNetCurrent | █▇█▇▇█▇▇▇▆▇▇▆▆▆▆▅▄▄▄▄▄▃▃▃▃▄▄▄▄▃▃▂▂▁▂▂▁ | 43.751 | 41.234 | 44.185 | 42.053 | 40.56 | 42.964 | 40.484 | 41.292 | 40.684 | 39.258 | 41.709 | 40.993 | 39.482 | 38.015 | 39.096 | 39.118 | 34.754 | 33.698 | 33.598 | 33.487 | 32.379 | 31.528 | 30.718 | 30.991 | 30.972 | 29.761 | 33.089 | 31.77 | 33.505 | 33.126 | 30.628 | 28.703 | 27.179 | 26.831 | 23.99 | 27.98 | 25.652 | 24.915 | NA | 25.029 | 24.774 | 26.352 | NA | NA | 23.702 | NA | NA | NA |
| us-gaap:PrepaidExpenseAndOtherAssetsCurrent | ▇▇███▇▇▇▇▇▆▆▆▆▃▃▄▃▃▃▃▃▃▄▄▄▃▃▄▄▃▂▂▂▁▁▁▂ | 36.841 | 37.056 | 40.851 | 40.007 | 39.53 | 38.482 | 35.822 | 36.81 | 36.03 | 35.454 | 32.535 | 32.956 | 32.972 | 33.508 | 20.011 | 20.427 | 21.906 | 20.944 | 19.706 | 20.642 | 20.701 | 19.815 | 17.03 | 21.755 | 21.061 | 22.158 | 18.762 | 20.705 | 22.481 | 23.781 | 18.777 | 12.843 | 14.428 | 12.411 | 9.978 | 11.025 | 11.852 | 12.318 | NA | 10.051 | 9.863 | 11.135 | NA | NA | 8.654 | 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:NoncurrentAssets | █▇█▇▆▄▄▅▅▅▅▅▅▅▅▅▅▄▄▅▅▄▄▄▃▃▄▄▄▃▃▂▂▂▁▁▁▁ | 436.01 | 425.506 | 430.351 | 421.267 | 406.763 | 367.698 | 368.946 | 370.842 | 375.955 | 375.365 | 375.345 | 380.665 | 382.4 | 385.794 | 381.306 | 381.035 | 376.892 | 368.962 | 361.665 | 370.775 | 370.6 | 366.51 | 360.163 | 357.192 | 347.58 | 343.458 | 360.795 | 357.735 | 353.703 | 346.226 | 341.231 | 331.803 | 328.743 | 328.123 | 311.222 | 306.684 | 304.874 | 311.182 | NA | 308.043 | NA | NA | 308.043 | NA | 280.564 | NA | NA | NA |
| us-gaap:PropertyPlantAndEquipmentGross | NA | NA | 1515.867 | 421.251 | 406.747 | 367.682 | 1366.782 | NA | NA | NA | 1300.503 | NA | NA | NA | 1233.756 | NA | NA | NA | 1136.47 | NA | NA | NA | 1070.111 | NA | NA | NA | 1047.59 | NA | NA | NA | 985.084 | NA | NA | NA | 889.229 | NA | NA | NA | NA | 836.047 | NA | NA | NA | NA | 759.901 | NA | NA | NA | |
| us-gaap:PropertyPlantAndEquipmentGross us-gaap:FiniteLivedIntangibleAssetsByMajorClass us-gaap:Assets | NA | NA | 1032.889 | NA | NA | NA | 958.612 | NA | NA | NA | 905.333 | NA | NA | NA | 850.296 | NA | NA | NA | 786.55 | NA | NA | NA | NA | NA | 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:PropertyPlantAndEquipmentGross us-gaap:FiniteLivedIntangibleAssetsByMajorClass,us-gaap:PropertyPlantAndEquipmentByType us-gaap:Assets,us-gaap:Building | NA | NA | 1.376 | NA | NA | NA | 1.252 | NA | NA | NA | 1.277 | NA | NA | NA | 1.334 | NA | NA | NA | 1.171 | NA | NA | NA | NA | NA | 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:PropertyPlantAndEquipmentGross us-gaap:FiniteLivedIntangibleAssetsByMajorClass,us-gaap:PropertyPlantAndEquipmentByType us-gaap:Assets,us-gaap:Equipment | NA | NA | 611.265 | NA | NA | NA | 566.936 | NA | NA | NA | 538.761 | NA | NA | NA | 510.327 | NA | NA | NA | 476.786 | NA | NA | NA | NA | NA | 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:PropertyPlantAndEquipmentGross us-gaap:FiniteLivedIntangibleAssetsByMajorClass,us-gaap:PropertyPlantAndEquipmentByType us-gaap:Assets,us-gaap:Land | NA | NA | 0.116 | NA | NA | NA | 0.106 | NA | NA | NA | 0.108 | NA | NA | NA | 0.113 | NA | NA | NA | 0.099 | NA | NA | NA | NA | NA | 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:PropertyPlantAndEquipmentGross us-gaap:FiniteLivedIntangibleAssetsByMajorClass,us-gaap:PropertyPlantAndEquipmentByType us-gaap:Assets,us-gaap:LeaseholdImprovements | NA | NA | 241.379 | NA | NA | NA | 227.388 | NA | NA | NA | 214.495 | NA | NA | NA | 200.184 | NA | NA | NA | 182.734 | NA | NA | NA | NA | NA | 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:PropertyPlantAndEquipmentGross us-gaap:FiniteLivedIntangibleAssetsByMajorClass,us-gaap:PropertyPlantAndEquipmentByType us-gaap:Assets,us-gaap:OfficeEquipment | NA | NA | 19.611 | NA | NA | NA | 18.169 | NA | NA | NA | 16.711 | NA | NA | NA | 14.591 | NA | NA | NA | 13.735 | NA | NA | NA | NA | NA | 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:PropertyPlantAndEquipmentGross us-gaap:FiniteLivedIntangibleAssetsByMajorClass,us-gaap:PropertyPlantAndEquipmentByType us-gaap:Assets,us-gaap:SoftwareAndSoftwareDevelopmentCosts | NA | NA | 10.609 | NA | NA | NA | 10.035 | NA | NA | NA | 9.963 | NA | NA | NA | 9.701 | NA | NA | NA | 9.523 | NA | NA | NA | NA | NA | 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:PropertyPlantAndEquipmentGross us-gaap:FiniteLivedIntangibleAssetsByMajorClass,us-gaap:PropertyPlantAndEquipmentByType us-gaap:Assets,us-gaap:TechnologyEquipment | NA | NA | 148.533 | NA | NA | NA | 134.726 | NA | NA | NA | 124.018 | NA | NA | NA | 114.046 | NA | NA | NA | 102.502 | NA | NA | NA | NA | NA | 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:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType us-gaap:ContractualRights | NA | NA | 482.978 | NA | NA | NA | 408.17 | NA | NA | NA | 395.17 | NA | NA | NA | 383.46 | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment | NA | NA | 1085.532 | NA | NA | NA | 997.853 | NA | NA | NA | 925.178 | NA | NA | NA | 852.474 | NA | NA | NA | 774.829 | NA | NA | NA | 709.975 | NA | NA | NA | 686.829 | NA | NA | NA | 643.891 | NA | NA | NA | 578.054 | NA | NA | NA | NA | 528.069 | NA | NA | NA | NA | 479.446 | NA | NA | NA | |
| us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap:FiniteLivedIntangibleAssetsByMajorClass us-gaap:Assets | NA | NA | 856.859 | NA | NA | NA | 790.033 | NA | NA | NA | 736.356 | NA | NA | NA | 680.114 | NA | NA | NA | 621.162 | NA | NA | NA | NA | NA | 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:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap:PropertyPlantAndEquipmentByType us-gaap:ContractualRights | NA | NA | 228.673 | NA | NA | NA | 207.82 | NA | NA | NA | 188.822 | NA | NA | NA | 172.36 | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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:PropertyPlantAndEquipmentNet | █▁▄ | 435.996 | 425.492 | 430.335 | NA | NA | NA | 368.929 | 370.825 | 375.936 | 375.346 | 375.325 | 381.004 | 382.73 | 385.77 | 381.282 | 381.01 | 376.867 | 368.938 | 361.641 | 370.749 | 370.573 | 366.482 | 360.136 | 357.163 | 347.55 | 343.429 | 360.761 | 357.699 | 353.663 | 346.185 | 341.193 | 331.763 | 328.702 | 328.08 | 311.175 | 306.635 | 304.823 | 311.122 | NA | 307.978 | 308.941 | 312.149 | NA | NA | 280.455 | NA | NA | NA |
| us-gaap:DeferredTaxAssetsLiabilitiesNet | NA | NA | 170.357 | NA | NA | NA | 162.866 | NA | NA | NA | 2.733 | NA | NA | NA | 17.616 | NA | NA | NA | 42.241 | NA | NA | NA | 45.142 | NA | NA | NA | 52.967 | NA | NA | NA | 56.182 | NA | NA | NA | 6.186 | NA | NA | NA | NA | 8.784 | NA | NA | NA | NA | 3.065 | 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:AccountsPayableCurrent | ▅▄▂▃▄▄▃▂▃▂▁▁▂▄▃▄▂▄▃▄▆█▄▆▆▇▄▆▇▆▅▄▆▆▅▅▃▆ | 14.601 | 12.19 | 9.775 | 11.983 | 12.171 | 13.102 | 11.075 | 9.849 | 11.57 | 9.619 | 8.519 | 8.262 | 10.33 | 12.964 | 11.592 | 12.314 | 9.284 | 12.286 | 11.551 | 13.019 | 16.293 | 19.025 | 12.401 | 15.35 | 15.489 | 16.752 | 13.287 | 16.303 | 16.969 | 16.441 | 14.098 | 12.176 | 15.979 | 16.665 | 14.734 | 13.88 | 11.287 | 15.316 | NA | 14.199 | 9.971 | 10.938 | NA | NA | 15.979 | NA | NA | NA |
| us-gaap:AccruedLiabilitiesCurrent | ▇▇█▇█▇█▇█▆█▇▇▇▇▇▇▆▇▆▆▅▅▆▅▅▄▃▄▂▃▂▃▂▂▁▂▁ | 48.014 | 49.656 | 51.029 | 47.714 | 52.492 | 49.239 | 51.301 | 49.115 | 51.615 | 45.564 | 51.431 | 46.728 | 47.447 | 46.198 | 47.947 | 47.449 | 49.412 | 45.146 | 47.149 | 41.79 | 43.502 | 40.896 | 38.355 | 45.616 | 40.913 | 38.214 | 32.151 | 31.257 | 34.754 | 27.221 | 31.465 | 23.935 | 27.552 | 24.346 | 26.519 | 20.807 | 25.468 | 20.48 | NA | 21.944 | 19.215 | 23.966 | NA | NA | 19.538 | NA | NA | NA |
| us-gaap:LiabilitiesCurrent | ▂█▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁▁▂▁▁▁▁▁▁▁▃▃▃▃▁▁▁▁▁ | 93.726 | 422.709 | 94.443 | 95.247 | 100.063 | 90.14 | 89.694 | 86.225 | 90.217 | 81.551 | 75.307 | 72.272 | 74.951 | 74.474 | 74.526 | 73.551 | 72.335 | 69.249 | 67.913 | 61.959 | 65.881 | 78.911 | 68.904 | 68.636 | 64.589 | 68.252 | 60.032 | 56.54 | 60.064 | 142.347 | 143.694 | 131.911 | 136.158 | 47.712 | 51.74 | 42.102 | 45.973 | 45.537 | NA | 47.843 | 39.1 | 43.108 | NA | NA | 41.66 | NA | NA | NA |
| us-gaap:OperatingLeaseLiabilityCurrent | ▇▅▅█▅▂▁▂▃▂ | 11.783 | 11.055 | 11.151 | 12.006 | 11.292 | 10.409 | 10.101 | 10.299 | 10.639 | 10.389 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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:OtherAccruedLiabilitiesCurrent | NA | NA | 24.168 | NA | NA | NA | 23.695 | NA | NA | NA | 24.02 | NA | NA | NA | 25.278 | NA | NA | NA | 47.149 | NA | NA | NA | 38.355 | NA | NA | NA | 32.151 | NA | NA | NA | 31.465 | NA | NA | NA | 26.519 | NA | NA | NA | NA | 21.944 | 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:LongTermDebt | NA | NA | 881.975 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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:LongtermDebtType ccoi:SeniorSecuredNotesDue2022 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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:UnsecuredLongTermDebt us-gaap:LongtermDebtType ccoi:SeniorUnsecuredNotesOf4.375Due2024 | ████▇▁▁▁ | 412.254 | 406.7 | 425.16 | 406.034 | 388.463 | 147.166 | 150.001 | 145.896 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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:UnsecuredLongTermDebt us-gaap:LongtermDebtType us-gaap:SecuredDebt | NA | NA | 444.492 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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:SecuredLongTermDebt us-gaap:LongtermDebtType ccoi:SeniorSecuredNotesDue2026 | ▄ | 497.025 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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:SecuredLongTermDebt us-gaap:LongtermDebtType us-gaap:SecuredDebt | NA | NA | 444.492 | 444.389 | 444.287 | NA | 444.088 | NA | NA | NA | 443.71 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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 | ▅▅▄▄▅▄▄▃▁▁▆▇▇▇▇▇▇▇▇▇▆▇██▆▆▅▅▅▅▅▂▂▂▂▂▃▂ | 19.346 | 19.221 | 14.792 | 16.8 | 19.943 | 17.815 | 15.327 | 13.014 | 7.588 | 5.795 | 25.38 | 26.717 | 27.35 | 27.196 | 27.596 | 28.351 | 28.909 | 29.062 | 28.043 | 26.519 | 24.728 | 27.576 | 30.977 | 29.961 | 25.125 | 22.858 | 21.775 | 21.227 | 21.367 | 20.536 | 19.965 | 10.775 | 10.828 | 10.438 | 10.067 | 9.913 | 11.26 | 10.376 | NA | 11.199 | 6.056 | 6.232 | NA | NA | 5.86 | NA | NA | NA |
| us-gaap:OperatingLeaseLiabilityNoncurrent | █▇▇▅▄▂▂▁▁▁ | 115.949 | 109.377 | 111.318 | 101.447 | 99.151 | 88.335 | 86.69 | 85.331 | 83.456 | 84.645 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:StockholdersEquity | ▁▁▂▂▂▃▃▃▃▃▃▄▄▄▄▄▅▅▅▅▅▅▅▅▆▆▇▇▇██▇▇█████ | -336.141 | -307.559 | -293.166 | -260.691 | -235.55 | -222.225 | -203.679 | -190.501 | -176.59 | -164.231 | -149.002 | -125.844 | -114.636 | -97.055 | -102.544 | -80.123 | -71.201 | -63.612 | -53.254 | -40.486 | -29.389 | -18.382 | -12.271 | 1.102 | 22.189 | 54.252 | 83.794 | 108.664 | 140.622 | 163.0 | 193.492 | 155.035 | 154.538 | 155.861 | 159.779 | 160.983 | 161.149 | 164.987 | NA | 164.001 | 158.639 | NA | NA | NA | 151.801 | NA | NA | NA |
| us-gaap:StockholdersEquity us-gaap:StatementEquityComponents us-gaap:AccumulatedTranslationAdjustment | ▆▅█▅▂▁▃▁▃▂▃▄▅█▆ | -4.74 | -6.516 | -1.306 | -7.498 | -12.906 | -15.819 | -12.326 | -15.676 | -10.967 | -12.753 | -10.928 | -8.672 | -8.187 | -1.989 | -4.6 | NA | NA | NA | -17.193 | NA | NA | NA | -14.693 | NA | NA | NA | -6.462 | NA | NA | NA | 2.136 | NA | NA | NA | 0.667 | NA | NA | NA | NA | -0.582 | NA | NA | NA | NA | 1.044 | NA | NA | NA |
| us-gaap:StockholdersEquity us-gaap:StatementEquityComponents us-gaap:AdditionalPaidInCapital | █▇▆▆▆▅▄▄▃▃▂▂▂▁▁ | 533.049 | 523.913 | 515.867 | 513.454 | 506.391 | 499.455 | 493.178 | 487.396 | 481.734 | 475.275 | 471.331 | 472.817 | 467.007 | 461.154 | 456.696 | NA | NA | NA | 442.799 | NA | NA | NA | 434.161 | NA | NA | NA | 460.576 | NA | NA | NA | 508.256 | NA | NA | NA | 497.349 | NA | NA | NA | NA | 489.021 | NA | NA | NA | NA | 482.737 | NA | NA | NA |
| us-gaap:StockholdersEquity us-gaap:StatementEquityComponents us-gaap:CommonStock | ██▄▄▄▄▄▄▄▁▁▁▁▁▁ | 0.048 | 0.048 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | NA | NA | NA | 0.045 | NA | NA | NA | 0.045 | NA | NA | NA | 0.046 | NA | NA | NA | 0.047 | NA | NA | NA | 0.047 | NA | NA | NA | NA | 0.046 | NA | NA | NA | NA | 0.046 | NA | NA | NA |
| us-gaap:StockholdersEquity us-gaap:StatementEquityComponents us-gaap:RetainedEarnings | ▁▂▂▃▄▅▅▆▆▆▇▇███ | -864.498 | -825.004 | -807.774 | -766.694 | -729.082 | -705.908 | -684.578 | -662.268 | -647.404 | -626.799 | -609.451 | -590.035 | -573.502 | -556.266 | -554.686 | NA | NA | NA | -478.905 | NA | NA | NA | -431.784 | NA | NA | NA | -370.366 | NA | NA | NA | -316.947 | NA | NA | NA | -338.284 | NA | NA | NA | NA | -324.484 | NA | NA | NA | NA | -332.026 | NA | NA | NA |
| us-gaap:CommonStockValue | ██▆▆▆▆▆▆▆▃▃▃▃▃▃▃▃▁▁▁▁▁▁▁▃▃▃▃▃▆▆▆▆▆▆▆▆▃ | 0.048 | 0.048 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | 0.045 | 0.045 | 0.045 | 0.045 | 0.045 | 0.045 | 0.045 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.046 | NA | 0.046 | 0.046 | 0.046 | NA | NA | 0.046 | NA | NA | NA |
| us-gaap:AdditionalPaidInCapitalCommonStock | █▇▇▇▆▆▅▅▄▄▄▄▃▃▃▂▂▂▂▂▂▁▁▁▂▃▃▄▄▅▆▆▆▆▆▅▅▅ | 533.049 | 523.913 | 515.867 | 513.454 | 506.391 | 499.455 | 493.178 | 487.396 | 481.734 | 475.275 | 471.331 | 472.817 | 467.007 | 461.154 | 456.696 | 452.369 | 447.852 | 445.976 | 442.799 | 442.125 | 440.2 | 436.793 | 434.161 | 431.223 | 440.401 | 456.016 | 460.576 | 467.846 | 480.794 | 496.453 | 508.256 | 505.787 | 503.241 | 500.352 | 497.349 | 494.458 | 491.494 | 490.474 | NA | 489.021 | 486.945 | 487.523 | NA | NA | 482.737 | NA | NA | NA |
| us-gaap:RetainedEarningsAccumulatedDeficit | ▁▂▂▂▃▃▃▄▄▄▄▅▅▅▅▅▆▆▆▆▆▆▇▇▇▇▇███████████ | -864.498 | -825.004 | -807.774 | -766.694 | -729.082 | -705.908 | -684.578 | -662.268 | -647.404 | -626.799 | -609.451 | -590.035 | -573.502 | -556.266 | -554.686 | -526.626 | -509.397 | -493.768 | -478.905 | -470.758 | -457.048 | -444.601 | -431.784 | -418.219 | -406.083 | -387.952 | -370.366 | -355.824 | -341.848 | -335.174 | -316.947 | -352.34 | -347.95 | -343.412 | -338.284 | -332.996 | -328.365 | -326.574 | NA | -324.484 | -329.908 | -330.189 | NA | NA | -332.026 | NA | NA | NA |
| us-gaap:StockIssuedDuringPeriodValueNewIssues | ▁█ | 0.0 | 0.001 | NA | NA | NA | NA | 0.0 | 0.0 | 0.001 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents us-gaap:CommonStock | ▁█ | 0.0 | 0.001 | NA | NA | NA | NA | 0.0 | 0.0 | 0.001 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue | █▇▅▆▅▄▃▃▄▁▃▃▃▂ | 8.476 | 7.831 | 6.431 | 7.147 | 6.666 | 5.559 | 5.415 | 5.311 | 5.714 | 3.771 | 4.83 | 5.292 | 5.149 | 4.161 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:NetCashProvidedByUsedInOperatingActivities | ▆█▅▄▆▃█▄▆▃▆▄▃▃▃▃▃▁▄▁ | 39.749 | 47.106 | 37.571 | 32.98 | 41.311 | 28.458 | 46.097 | 33.443 | 40.632 | 28.637 | 40.726 | 31.745 | 31.271 | 30.179 | 31.36 | 28.783 | 28.045 | 23.514 | 33.879 | 22.833 | NA | NA | NA | NA | 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:NetCashProvidedByUsedInInvestingActivities | ▁▂▂▄▃▄▆▅▅▄▅▅▅▃▆▅▅▄█▇ | -17.217 | -15.444 | -15.86 | -13.296 | -13.93 | -12.866 | -9.899 | -12.051 | -11.72 | -13.288 | -10.937 | -12.107 | -11.988 | -14.905 | -10.618 | -10.927 | -12.007 | -12.249 | -7.195 | -8.745 | NA | NA | NA | NA | 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:NetCashProvidedByUsedInFinancingActivities | █▁▄▄▅▄▄▄█▄▄▆▄▄▄▄▄▄█▅ | 112.793 | -163.667 | -45.768 | -44.977 | 13.315 | -38.572 | -34.124 | -32.817 | 120.77 | -31.809 | -37.51 | 40.883 | -29.127 | -26.791 | -24.982 | -24.998 | -24.516 | -22.771 | 100.76 | -20.925 | NA | NA | NA | NA | 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:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect | █▁▄▄▅▄▄▄█▄▄▆ | 135.983 | -133.321 | -21.992 | -23.733 | 41.91 | -24.306 | 3.151 | -13.008 | 150.141 | -16.955 | -8.465 | 60.276 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:DeferredIncomeTaxExpenseBenefit | ▄▅▄▃▅▅▅▅▅▅▅▅▅▅█▅▅▅▄▅▅▅▁▅▄▄▃▄▄▄ | -0.939 | 4.497 | -1.818 | -2.153 | 1.814 | 2.439 | 2.873 | 4.454 | 2.259 | 2.572 | 3.59 | 2.712 | 2.192 | 2.623 | 14.844 | 3.209 | 3.397 | 3.229 | 0.771 | 2.82 | 3.31 | 2.323 | -11.539 | 2.355 | 0.653 | 0.822 | -5.074 | 1.139 | -0.457 | 1.229 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:DepreciationDepletionAndAmortization | ███▇▆▅▆▆▆▆▇▆▆▅▅▅▅▄▆▄▄▃▄▃▃▃▃▃▃▃▂▂▂▂▂▁▁▁ | 22.096 | 21.97 | 22.455 | 21.619 | 19.896 | 19.508 | 20.001 | 20.006 | 19.979 | 20.263 | 20.953 | 20.276 | 20.216 | 19.788 | 19.343 | 19.147 | 18.897 | 18.538 | 20.074 | 18.804 | 18.604 | 17.753 | 18.01 | 17.634 | 17.371 | 17.513 | 17.544 | 17.431 | 17.301 | 17.204 | 16.56 | 16.024 | 15.9 | 15.874 | 16.125 | 15.61 | 15.503 | 15.239 | NA | 15.136 | 15.188 | 14.734 | 14.791 | NA | 14.812 | 14.736 | 14.099 | NA |
| us-gaap:IncreaseDecreaseInAccountsReceivable | ▇▃▆▅▂▇▄▅▆▃▅▆▆▃▄█▅▅▅▅▆▅▅▅▅▃▆▄▅▇▆▆▅▇▁▆▆▄ | 2.33 | -2.42 | 1.6 | 1.009 | -2.697 | 2.79 | -1.11 | 1.048 | 1.259 | -2.264 | 0.924 | 1.539 | 2.096 | -1.355 | -0.156 | 3.976 | 0.384 | -0.043 | 0.705 | 1.033 | 1.058 | 0.387 | -0.001 | 0.008 | 0.997 | -2.123 | 1.857 | -0.889 | 0.416 | 2.554 | 1.784 | 1.1 | 0.234 | 3.175 | -4.21 | 2.04 | 1.349 | -0.426 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:NetCashProvidedByUsedInOperatingActivities | ▆█▅▄▆▃█▄▆▃▆▄▃▃▃▃▃▁▄▁ | 39.749 | 47.106 | 37.571 | 32.98 | 41.311 | 28.458 | 46.097 | 33.443 | 40.632 | 28.637 | 40.726 | 31.745 | 31.271 | 30.179 | 31.36 | 28.783 | 28.045 | 23.514 | 33.879 | 22.833 | NA | NA | NA | NA | 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:ProfitLoss | ▂█▁▁▅▅▅▇▅▅▅▅▅▅ | -2.493 | 18.851 | -6.62 | -4.955 | 8.564 | 9.227 | 7.466 | 13.701 | 7.136 | 9.217 | 7.1 | 8.231 | 6.552 | 6.784 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 2.115 | NA | NA | NA | NA | -0.883 | 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:NetCashProvidedByUsedInInvestingActivities | ▁▂▂▄▃▄▆▅▅▄▅▅▅▃▆▅▅▄█▇ | -17.217 | -15.444 | -15.86 | -13.296 | -13.93 | -12.866 | -9.899 | -12.051 | -11.72 | -13.288 | -10.937 | -12.107 | -11.988 | -14.905 | -10.618 | -10.927 | -12.007 | -12.249 | -7.195 | -8.745 | NA | NA | NA | NA | 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:PaymentsToAcquirePropertyPlantAndEquipment | █▇▇▆▆▆▄▅▅▆▄▅▅▇▄▄▅▅▂▃▆▇▁▂▄▆▆▇▇▇▄▄▅▇▄▅▄▅ | 17.217 | 15.444 | 15.86 | 13.296 | 13.93 | 12.866 | 9.899 | 12.051 | 11.72 | 13.288 | 10.937 | 12.107 | 11.988 | 14.905 | 10.618 | 10.927 | 12.007 | 12.249 | 7.195 | 8.745 | 14.26 | 15.034 | 4.962 | 6.838 | 10.866 | 12.916 | 13.022 | 15.402 | 15.985 | 15.623 | 10.095 | 10.165 | 12.455 | 16.316 | 10.286 | 11.187 | 10.575 | 12.289 | NA | 10.424 | 9.437 | 13.153 | 12.842 | NA | 11.718 | 16.518 | 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:NetCashProvidedByUsedInFinancingActivities | █▁▄▄▅▄▄▄█▄▄▆▄▄▄▄▄▄█▅ | 112.793 | -163.667 | -45.768 | -44.977 | 13.315 | -38.572 | -34.124 | -32.817 | 120.77 | -31.809 | -37.51 | 40.883 | -29.127 | -26.791 | -24.982 | -24.998 | -24.516 | -22.771 | 100.76 | -20.925 | NA | NA | NA | NA | 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:RepaymentsOfLongTermDebt | ▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁▁▁█▂▁ | 1.969 | 2.378 | 2.692 | 2.727 | 2.562 | 2.566 | 2.659 | 2.574 | 2.387 | 2.387 | 2.549 | 2.634 | 2.289 | 1.965 | 1.619 | 1.232 | 0.733 | 0.218 | 0.0 | 0.0 | 19.019 | 2.184 | 0.575 | NA | 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:PaymentsOfDividends | ██▇▇▇▆▆▆▆▅▅▅▅▅▄▄▄▄▃▃▃▃▃▃▄▃▃▂▁▄ | 37.001 | 36.081 | 34.46 | 32.657 | 31.738 | 30.557 | 29.776 | 28.565 | 27.741 | 26.565 | 26.516 | 24.764 | 23.788 | 22.819 | 21.833 | 20.879 | 19.946 | 18.999 | 18.199 | 17.169 | 16.671 | 16.171 | 16.045 | 15.296 | 18.972 | 16.001 | 14.19 | 13.792 | 7.882 | 18.352 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:PaymentsForRepurchaseOfCommonStock | NA | NA | 4.225 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 0.0 | NA | NA | NA | 2.826 | NA | NA | NA | 0.0 | 12.169 | 19.106 | 8.119 | 10.555 | 15.9 | 17.888 | 14.196 | NA | NA | NA | NA | 0.0 | 0.0 | 1.3 | NA | NA | 0.035 | 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:LongtermDebtType ccoi:SeniorSecuredNotesDue2022 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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:DebtInstrumentInterestRateStatedPercentage us-gaap:LongtermDebtType ccoi:SeniorSecuredNotesDue2026 | ▄ | 3.5e-06 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 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:DebtInstrumentInterestRateStatedPercentage us-gaap:LongtermDebtType ccoi:SeniorUnsecuredNotesOf4.375Due2024 | ▄ | 4.375e-06 | NA | NA | NA | 4.375e-08 | NA | NA | 4.375e-08 | 4.375e-08 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| 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 | 48000.0 | 48000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 | 45000.0 | 45000.0 | 45000.0 | 45000.0 | 45000.0 | 45000.0 | 45000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 |
| Percentage of CommonStockValue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 0.0 | 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 | 0.0 | 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 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 |
| Value | 46 | 46 | 45 | 46 | 46 | 46 | 46 | 45 | 45 | 45 | 45 | 45 | 45 | 44 | 45 | 44 | 44 | 44 | 44 | 44 | 44 | 44 | 44 | 45 | 45 | 45 | 45 | 46 | 46 | 48 | 46 | 46 | 46 | 45 | 45 | 45 | 45 | 45 | 45 | 45 | 45 | 44 | 44 | 45 | 44 | 44 | 44 |
| 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 | 100.0 | 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 |
| Value | 45 | 45 | 46 | 46 | 46 | 46 | 45 | 45 |
| Percentage of WeightedAverageNumberOfDilutedSharesOutstanding | 0.0 | 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 | 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 |
| Value | 46 | 46 | 45 | 45 | 45 | 45 | 45 | 45 | 45 | 45 | 45 | 45 | 44 | 44 | 44 | 44 | 44 | 44 | 44 | 44 | 44 | 44 | 44 | 44 | 45 | 45 | 45 | 45 | 46 | 46 | 46 | 46 | 45 | 45 | 45 | 45 | 45 | 45 | 45 | 45 | 45 | 44 | 44 | 44 | 44 | 44 | 44 |
| 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 | 100.0 | 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 |
| Value | 45 | 45 | 45 | 45 | 45 | 45 | 45 | 45 |
| Percentage of WeightedAverageNumberOfSharesOutstandingBasic | 0.0 | 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 | 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 |
| Value | 36063.0 | 77832.0 | 18496.0 | 93070.0 | 37606.0 | 36381.0 | 69208.0 | 30836.0 | 43308.0 | 77284.0 | 54908.0 | 62175.0 | 48534.0 | 75687.0 | 64349.0 | 111900.0 | 136220.0 | 120530.0 | 98102.0 |
| Percentage of AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2020-03-31 | 2019-06-30 | 2018-03-31 | 2017-09-30 | 2017-06-30 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2012-03-31 | 2011-06-30 | 2011-03-31 |
| Value | 28019.0 | 392410.0 | 11884.0 | 37494.0 | 78087.0 | 195.0 | 138910.0 | 617240.0 | 369240.0 | 3360.0 | 700000.0 | 200000.0 | 1200000.0 |
| Percentage of AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount | 77.7 | 504.2 | 12.8 | 103.1 | 101.0 | 0.4 | 223.4 | 453.1 | 306.3 | 3.4 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 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 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2011-06-30 | 2010-06-30 |
| Value | -0.05 | -0.14 | -0.11 | 0.19 | 0.16 | 0.3 | 0.16 | 0.2 | 0.16 | 0.18 | 0.15 | 0.15 | -0.14 | 0.08 | 0.1 | -0.01 | 0 | 0.03 | 0 | 1.14 | 0.05 | 0.03 | 0.01 | 0.05 | -0.02 |
| 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 | 0.0 | 100.0 | 0.0 | 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 |
| Value | -0.14 | -0.11 | 0.19 | 0.2 |
| Percentage of EarningsPerShareBasic | 100.0 | 100.0 | 100.0 | 0.0 |
| Period End | 2021-06-30 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 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 | 2011-06-30 | 2010-06-30 |
| Value | -0.05 | -0.15 | -0.11 | 180.0 | 0.16 | 0.3 | 0.16 | 0.16 | 0.18 | 0.14 | -0.14 | 0.08 | 0.1 | 0.06 | 0.07 | 0.02 | -0.04 | -0.01 | 0 | 0.03 | 0 | 1.1 | 0.05 | 0.03 | 0.01 | 0.05 | -0.02 |
| 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 | 0.0 | 100.0 | 0.0 | 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 |
| Value | -0.14 | -0.11 | 0.18 | 0.2 |
| Percentage of EarningsPerShareDiluted | 93.3 | 100.0 | 0.1 | 0.0 |
| Period End | 2021-03-31 | 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 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 |
| Value | 0.41 | 0.2 | 0.16 | 0.3 | 0.16 | 0.2 | 0.16 | 0.18 | 0.15 | 0.15 | -0.14 | 0.08 | 0.1 | 0.09 | 0.06 | 0.08 | 0.09 | 0.08 | 0.09 | 0.07 | 0.02 | -0.04 | 0 | 0.03 | 0 | 0.05 | 0.03 | 0.01 | -0.01 | 0 | -0.04 | -0.05 | -0.05 | 0.12 | 0.01 | 0.05 | -0.01 | -0.01 | 0.06 | -0.01 | -0.02 | -0.01 |
| Percentage of EarningsPerShareBasicAndDiluted | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 0.0 | 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 |
| 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 | 6.874 | 7.307 | 5.846 | 6.522 | 6.082 | 5.075 | 4.94 | 4.796 | 5.29 | 3.434 | 4.408 | 4.821 | 4.695 | 3.784 |
| 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 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 4.6 | 5.0 | 4.1 | 4.6 | 4.3 | 3.6 | 3.5 | 3.5 | 3.9 | 2.6 | 3.3 | 3.7 | 3.6 | 2.9 |
| 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 |
| Value | 0.136 | 2.076 | 0.316 | 0.346 | 0.305 | 0.252 | 0.306 | 0.282 | 0.226 | 0.18 | 0.224 | 0.25 | 0.232 | 0.189 |
| Percentage of AllocatedShareBasedCompensationExpense | 2.0 | 28.4 | 5.4 | 5.3 | 5.0 | 5.0 | 6.2 | 5.9 | 4.3 | 5.2 | 5.1 | 5.2 | 4.9 | 5.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.1 | 1.4 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.1 | 0.2 | 0.2 | 0.2 | 0.1 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:NetworkOperations | 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 |
| Value | 6.738 | 5.231 | 5.53 | 6.176 | 5.778 | 4.823 | 4.634 | 4.515 | 5.063 | 3.254 | 4.184 | 4.571 | 4.463 | 3.595 |
| Percentage of AllocatedShareBasedCompensationExpense | 98.0 | 71.6 | 94.6 | 94.7 | 95.0 | 95.0 | 93.8 | 94.1 | 95.7 | 94.8 | 94.9 | 94.8 | 95.1 | 95.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 4.6 | 3.6 | 3.8 | 4.3 | 4.1 | 3.4 | 3.3 | 3.3 | 3.8 | 2.4 | 3.2 | 3.5 | 3.5 | 2.8 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:SellingGeneralAndAdministrativeExpenses | 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 |
| Value | -0.717 | 13 | -0.428 | 0.453 | 11 | 5.734 | 10 | 8.992 | 8.922 | 7.392 | 4.844 | 7.746 | 0.354 | 9.395 | -4.915 | 7.44 | 10 | 5.464 | -1.403 | 4.147 | 2.257 | 7.428 | -0.266 | 3.389 | 2.523 | -8.981 | -3.41 | -5.218 | 1.164 | -0.337 | 53 | 4.463 | 1.933 | -1.432 | 0.917 | 1.407 | -4.859 | -0.467 | 3.286 | -3.037 | 2.96 | 2.707 |
| Percentage of ComprehensiveIncomeNetOfTax | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 RevenueFromContractWithCustomerIncludingAssessedTax | -0.5 | 9.3 | -0.3 | 0.3 | 8.1 | 4.1 | 7.7 | 6.6 | 6.6 | 5.5 | 3.7 | 6.0 | 0.3 | 7.3 | -3.9 | 6.1 | 8.7 | 4.7 | -1.3 | 4.0 | 2.3 | 7.6 | -0.3 | 3.3 | 2.6 | -9.2 | -3.5 | -5.5 | 1.2 | -0.4 | 59.2 | 5.1 | 2.3 | -1.7 | 1.1 | 1.8 | -6.2 | -0.6 | 4.2 | -3.9 | 3.9 | 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 |
| Value | 56 | 57 | 54 | 54 | 53 | 55 | 55 | 55 | 54 | 54 | 55 | 54 | 54 | 54 | 53 | 53 | 51 | 50 |
| 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 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 38.0 | 38.9 | 38.1 | 38.3 | 38.2 | 39.7 | 39.9 | 40.3 | 40.4 | 40.4 | 42.2 | 42.0 | 42.1 | 42.6 | 43.1 | 43.6 | 42.7 | 43.2 |
| 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 |
| Value | 54 | 54 | 53 | 55 | 55 | 55 | 54 | 54 |
| Percentage of CostOfGoodsAndServicesSold | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 38.1 | 38.3 | 38.2 | 39.7 | 39.9 | 40.3 | 40.4 | 40.4 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:Unaudited | 38.1 | 38.3 | 38.2 | 39.7 | 39.9 | 40.3 | 40.4 | 40.4 |
| 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 | 119 | 120 | 116 | 115 | 113 | 115 | 112 | 111 | 112 | 110 | 109 | 108 | 108 | 108 | 105 | 105 | 101 | 100 | 101 | 97 | 96 | 94 | 91 | 90 | 88 | 88 | 83 | 82 | 80 | 80 | 77 | 75 | 74 | 74 | 73 | 71 | 70 | 70 | 68 | 67 | 66 | 66 | 63 | 63 | 61 |
| Percentage of CostsAndExpenses | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 RevenueFromContractWithCustomerIncludingAssessedTax | 80.9 | 82.1 | 81.0 | 81.4 | 80.6 | 81.7 | 80.2 | 81.2 | 83.8 | 82.2 | 83.2 | 83.2 | 83.8 | 84.1 | 83.9 | 85.9 | 85.0 | 85.9 | 96.5 | 94.8 | 97.5 | 97.2 | 86.5 | 87.5 | 89.8 | 90.8 | 86.5 | 85.8 | 84.9 | 86.1 | 86.6 | 85.7 | 86.5 | 88.3 | 88.9 | 89.9 | 90.0 | 92.2 | 86.2 | 87.6 | 88.5 | 90.0 | 91.7 | 94.4 | 95.4 |
| Period End | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2011-06-30 |
| Value | -3868000.0 | 0 | 0 | -638000.0 | -587000.0 | -10144000.0 | 0 | 0 | 0 | -10144000.0 | 2739000.0 |
| Percentage of GainsLossesOnExtinguishmentOfDebt | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 100.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | -2.6 | 0.0 | 0.0 | -0.5 | -0.6 | -10.4 | 0.0 | 0.0 | 0.0 | -10.4 | 3.6 |
| Period End | 2021-06-30 |
| Value | -10830000.0 |
| Percentage of GainsLossesOnExtinguishmentOfDebt | 0.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | -7.3 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:SecuredDebtOne | 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 |
| Value | 0.828 | 28 | -4.01 | -4.084 | 14 | 17 | 13 | 24 | 16 | 18 | 17 | 16 | 15 | 14 | 14 | 12 | 12 | 12 | 5.17 | 11 | 13 | 11 | 11 | 9.343 | 6.078 | -5.176 | 7.757 | 7.874 | 7.578 | 8.436 | 8.629 | 8.011 | 7.943 | 6.195 |
| Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 RevenueFromContractWithCustomerIncludingAssessedTax | 0.6 | 19.4 | -2.8 | -2.9 | 10.0 | 12.6 | 9.4 | 17.9 | 12.1 | 14.0 | 13.4 | 12.8 | 11.9 | 11.0 | 12.0 | 9.9 | 10.6 | 10.6 | 4.9 | 11.6 | 13.4 | 11.7 | 11.1 | 9.1 | 6.2 | -5.3 | 8.0 | 8.2 | 8.0 | 9.1 | 9.6 | 9.1 | 9.3 | 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 |
| Value | -2.071 | 26 | -7.264 | -6.555 | 11 | 12 | 10 | 18 | 10 | 12 | 10 | 11 | 9.17 | 9.923 | 8.479 | 7.086 | 7.925 | 7.629 | 4.535 | 6.379 | 7.603 | 5.743 | 6.332 | 5.567 | 1.535 | -0.723 | 0.871 | 1.092 | 0.787 | 1.741 | 2.018 | 2.301 | 1.974 |
| 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 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | -1.4 | 17.9 | -5.0 | -4.6 | 8.0 | 9.1 | 7.7 | 13.8 | 7.6 | 9.5 | 8.2 | 8.8 | 7.1 | 7.7 | 6.8 | 5.8 | 6.6 | 6.5 | 4.3 | 6.2 | 7.7 | 5.9 | 6.0 | 5.4 | 1.6 | -0.7 | 0.9 | 1.1 | 0.8 | 1.9 | 2.2 | 2.6 | 2.3 |
| 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 |
| Value | -2899000.0 | -2301000.0 | -3254000.0 | -2471000.0 | -2814000.0 | -4954000.0 | -2467000.0 | -5497000.0 | -6152000.0 | -5982000.0 | -6782000.0 | -5227000.0 | -6276000.0 | -4212000.0 | -6505000.0 | -5124000.0 | -4765000.0 | -4737000.0 | -635000.0 | -5592000.0 | -5627000.0 | -5644000.0 | -5395000.0 | -3776000.0 | -4543000.0 | 4453000.0 | -6886000.0 | -6782000.0 | -6791000.0 | -6695000.0 | -6611000.0 | -5710000.0 | -5969000.0 | -5501000.0 |
| Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 RevenueFromContractWithCustomerIncludingAssessedTax | -2.0 | -1.6 | -2.3 | -1.7 | -2.0 | -3.5 | -1.8 | -4.0 | -4.6 | -4.5 | -5.1 | -4.0 | -4.9 | -3.3 | -5.2 | -4.2 | -4.0 | -4.0 | -0.6 | -5.4 | -5.7 | -5.8 | -5.1 | -3.7 | -4.6 | 4.6 | -7.1 | -7.1 | -7.2 | -7.2 | -7.4 | -6.5 | -7.0 | -6.5 |
| 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 | 2010-06-30 |
| Value | 0.422 | 7.35 | -0.644 | -1.6 | 2.735 | 3.608 | 3.303 | 5.254 | 3.044 | 3.554 | 3.762 | 3.194 | 2.618 | 3.139 | 14 | 3.436 | 3.608 | 3.493 | 0.643 | 2.92 | 3.379 | 2.389 | 3.852 | 2.406 | 0.695 | 0.862 | 1.223 | 1.276 | -0.421 | 1.616 | -50.581 | 0.179 | 0.367 | 0.333 | 1.05 | -0.492 | 0.752 | -0.56 | -3.122 | 0.423 | 0.458 | 0.281 | -0.909 | 0.087 | 0.099 |
| 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 RevenueFromContractWithCustomerIncludingAssessedTax | 0.3 | 5.0 | -0.4 | -1.1 | 1.9 | 2.6 | 2.4 | 3.8 | 2.3 | 2.6 | 2.8 | 2.5 | 2.0 | 2.4 | 11.7 | 2.8 | 3.0 | 3.0 | 0.6 | 2.8 | 3.4 | 2.5 | 3.7 | 2.3 | 0.7 | 0.9 | 1.3 | 1.3 | -0.4 | 1.7 | -56.3 | 0.2 | 0.4 | 0.4 | 1.3 | -0.6 | 1.0 | -0.7 | -3.9 | 0.5 | 0.6 | 0.4 | -1.3 | 0.1 | 0.2 |
| 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 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 14 | 15 | 16 | 15 | 15 | 15 | 15 | 15 | 13 | 13 | 13 | 12 | 12 | 12 | 12 | 12 | 12 | 11 | 10 | 9.891 | 10 | 10 | 10 | 10 | 9.692 | 11 | 12 | 12 | 13 | 11 | 11 | 10 | 10 | 9.869 | 9.321 | 9.015 | 8.988 | 8.993 | 8.838 | 8.953 | 9.135 | 7.585 | 4.342 | 4.1 | 4.148 |
| 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 RevenueFromContractWithCustomerIncludingAssessedTax | 9.6 | 10.8 | 11.1 | 11.1 | 11.0 | 10.8 | 10.8 | 11.1 | 10.1 | 10.0 | 10.2 | 9.8 | 9.6 | 9.6 | 9.8 | 10.0 | 10.1 | 10.1 | 10.1 | 9.6 | 10.4 | 10.4 | 9.8 | 9.7 | 9.8 | 11.6 | 12.6 | 13.2 | 14.6 | 12.2 | 12.4 | 12.0 | 11.9 | 11.7 | 11.3 | 11.3 | 11.6 | 11.7 | 11.2 | 11.6 | 12.1 | 10.3 | 6.3 | 6.1 | 6.4 |
| 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 |
| Value | -2.493 | 18 | -6.62 | -4.955 | 8.564 | 9.227 | 7.465 | 13 | 7.136 | 9.217 | 7.1 | 8.231 | 6.552 | 6.784 | -6.227 | 3.65 | 4.317 | 4.136 | 2.48 | 3.459 | 4.224 | 3.354 | 2.48 | 3.161 | 0.84 | -1.585 | -0.352 | -0.184 | 1.208 | 0.125 | 52 | 2.122 | 1.607 | 0.361 | -0.276 | -0.094 | -1.791 | -2.09 | -2.09 | 5.424 | 0.281 | 2.115 | -0.278 | -0.278 | 2.584 | -0.462 | -0.883 | -0.57 |
| 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 | 100.0 | 100.0 | 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 RevenueFromContractWithCustomerIncludingAssessedTax | -1.7 | 12.8 | -4.6 | -3.5 | 6.1 | 6.5 | 5.3 | 10.0 | 5.3 | 6.9 | 5.4 | 6.3 | 5.1 | 5.3 | -5.0 | 3.0 | 3.6 | 3.5 | 2.4 | 3.4 | 4.3 | 3.4 | 2.4 | 3.1 | 0.9 | -1.6 | -0.4 | -0.2 | 1.3 | 0.1 | 58.5 | 2.4 | 1.9 | 0.4 | -0.3 | -0.1 | -2.3 | -2.7 | -2.7 | 6.9 | 0.4 | 2.8 | -0.4 | -0.4 | 3.7 | -0.7 | -1.4 | -0.9 |
| 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 |
| Value | -2.493 | 18 | -6.62 | -4.955 | 8.564 | 9.227 | 7.466 | 13 | 7.136 | 9.217 | 7.1 | 8.231 | 6.552 | 6.784 |
| 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 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | -1.7 | 12.8 | -4.6 | -3.5 | 6.1 | 6.5 | 5.3 | 10.0 | 5.3 | 6.9 | 5.4 | 6.3 | 5.1 | 5.3 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax 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 | 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 |
| Value | -6.62 | -6.555 | 8.564 | 9.227 | 7.465 | 13 | 7.136 | 9.217 |
| Percentage of NetIncomeLossAvailableToCommonStockholdersBasic | 100.0 | 132.3 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | -4.6 | -4.6 | 6.1 | 6.5 | 5.3 | 10.0 | 5.3 | 6.9 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:Unaudited | -4.6 | -4.6 | 6.1 | 6.5 | 5.3 | 10.0 | 5.3 | 6.9 |
| 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 |
| Value | 28 | 26 | 27 | 26 | 27 | 25 | 28 | 25 | 22 | 24 | 22 | 22 | 21 | 20 | 20 | 17 | 19 | 18 | 16 | 16 | 17 | 15 | 16 | 15 | 10 | 10 | 13 | 13 | 14 | 12 | 12 | 12 | 11 | 9.905 | 9.169 | 8.032 | 7.801 | 5.968 | 5.968 | 10 | 9.576 | 8.671 | 7.358 | 7.358 | 5.864 | 3.749 | 2.981 | 2.688 |
| 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 | 100.0 | 100.0 | 100.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 19.1 | 17.9 | 19.0 | 18.3 | 19.6 | 18.3 | 20.0 | 18.8 | 16.3 | 18.2 | 16.9 | 17.1 | 16.5 | 16.0 | 16.4 | 14.4 | 15.9 | 15.9 | 15.4 | 15.6 | 17.7 | 16.1 | 15.4 | 15.1 | 10.9 | 10.8 | 13.5 | 14.2 | 15.1 | 13.9 | 13.4 | 14.3 | 13.5 | 11.7 | 11.1 | 10.1 | 10.0 | 7.8 | 7.8 | 13.8 | 12.4 | 11.5 | 10.0 | 10.0 | 8.4 | 5.6 | 4.6 | 4.3 |
| 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 | 27 | 26 | 27 | 25 | 28 | 25 | 22 | 24 |
| Percentage of OperatingIncomeLoss | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 19.0 | 18.3 | 19.6 | 18.3 | 20.0 | 18.8 | 16.3 | 18.2 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:Unaudited | 19.0 | 18.3 | 19.6 | 18.3 | 20.0 | 18.8 | 16.3 | 18.2 |
| 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 | 2011-06-30 | 2010-06-30 |
| Value | -2.493 | 18 | -6.62 | -4.955 | 8.564 | 9.227 | 7.466 | 13 | 7.136 | 9.217 | 7.1 | 8.231 | 6.552 | 6.784 | 2.115 | -0.883 |
| Percentage of ProfitLoss | 100.0 | 100.0 | 100.0 | 100.0 | 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 RevenueFromContractWithCustomerIncludingAssessedTax | -1.7 | 12.8 | -4.6 | -3.5 | 6.1 | 6.5 | 5.3 | 10.0 | 5.3 | 6.9 | 5.4 | 6.3 | 5.1 | 5.3 | 2.8 | -1.4 |
| 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 | 2012-03-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2011-03-30 | 2010-12-31 | 2010-09-30 | 2010-06-30 | 2010-03-31 |
| Value | 147 | 146 | 143 | 142 | 140 | 140 | 140 | 136 | 134 | 134 | 132 | 130 | 129 | 128 | 125 | 122 | 119 | 117 | 105 | 103 | 98 | 97 | 105 | 103 | 98 | 97 | 96 | 95 | 94 | 92 | 89 | 87 | 85 | 84 | 82 | 79 | 77 | 76 | 76 | 79 | 77 | 75 | 73 | 73 | 69 | 66 | 64 | 62 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 RevenueFromContractWithCustomerIncludingAssessedTax | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Value | 0.139 | 0.107 | 0.12 | 0.119 | 0.146 | 0.137 | 0.13 | 0.108 | 0.126 | 0.111 | 0.148 | 0.147 | 0.163 | 0.175 | 0.19 | 0.206 | 0.211 | 0.231 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.2 | 0.2 | 0.2 | 0.2 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.2 | 0.2 | 0.2 | 0.2 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:NonCoreServices | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Value | 36 | 36 | 36 | 37 | 37 | 37 | 37 | 37 | 37 | 36 | 36 | 36 | 36 | 36 | 35 | 34 | 33 | 33 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 24.8 | 25.0 | 25.5 | 26.1 | 26.3 | 26.5 | 26.7 | 27.3 | 27.6 | 27.5 | 27.7 | 27.8 | 27.9 | 28.1 | 28.5 | 28.4 | 28.4 | 28.5 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 24.8 | 25.0 | 25.5 | 26.1 | 26.3 | 26.5 | 26.7 | 27.3 | 27.6 | 27.5 | 27.7 | 27.8 | 27.9 | 28.1 | 28.5 | 28.4 | 28.4 | 28.5 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:OffNetServices | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Value | 111 | 109 | 107 | 105 | 103 | 103 | 102 | 99 | 97 | 97 | 95 | 93 | 93 | 92 | 89 | 87 | 85 | 83 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 75.1 | 74.9 | 74.4 | 73.9 | 73.6 | 73.4 | 73.2 | 72.6 | 72.3 | 72.5 | 72.2 | 72.1 | 71.9 | 71.8 | 71.4 | 71.5 | 71.5 | 71.3 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 75.1 | 74.9 | 74.4 | 73.9 | 73.6 | 73.4 | 73.2 | 72.6 | 72.3 | 72.5 | 72.2 | 72.1 | 71.9 | 71.8 | 71.4 | 71.5 | 71.5 | 71.3 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:OnNetServices | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Value | 0.014 | 0.018 | 0.015 | 0.012 | 0.009 | 0.011 | 0.008 | 0.004 | 0.015 | 0.026 | 0.02 | 0.016 | 0.014 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 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 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 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 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:NonCoreServices srt:Europe | 100.0 | 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 |
| Value | 0.125 | 0.089 | 0.105 | 0.107 | 0.137 | 0.126 | 0.122 | 0.104 | 0.111 | 0.085 | 0.128 | 0.131 | 0.149 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:NonCoreServices srt:NorthAmerica | 100.0 | 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 |
| Value | 0.263 | 0.271 | 0.257 | 0.24 | 0.01 | 0.226 | 0.196 | 0.188 | 0.211 | 0.182 | 0.167 | 0.146 | 0.137 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.2 | 0.2 | 0.2 | 0.2 | 0.0 | 0.2 | 0.1 | 0.1 | 0.2 | 0.1 | 0.1 | 0.1 | 0.1 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.2 | 0.2 | 0.2 | 0.2 | 0.0 | 0.2 | 0.1 | 0.1 | 0.2 | 0.1 | 0.1 | 0.1 | 0.1 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:OffNetServices srt:AsiaPacific | 100.0 | 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 |
| Value | 4.494 | 4.592 | 4.471 | 4.422 | 4.216 | 4.143 | 4.131 | 4.053 | 4.113 | 4.026 | 4.005 | 3.945 | 3.942 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 3.0 | 3.1 | 3.1 | 3.1 | 3.0 | 2.9 | 2.9 | 3.0 | 3.1 | 3.0 | 3.0 | 3.0 | 3.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 3.0 | 3.1 | 3.1 | 3.1 | 3.0 | 2.9 | 2.9 | 3.0 | 3.1 | 3.0 | 3.0 | 3.0 | 3.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:OffNetServices srt:Europe | 100.0 | 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 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 0.049 | 0.016 | 0.226 | 0.011 | 0.007 | 0.005 | 0.003 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.0 | 0.0 | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.0 | 0.0 | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:OffNetServices srt:LatinAmerica | 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 |
| Value | 31 | 31 | 31 | 32 | 32 | 32 | 33 | 33 | 32 | 32 | 32 | 32 | 32 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 21.6 | 21.7 | 22.2 | 22.8 | 23.1 | 23.4 | 23.6 | 24.2 | 24.4 | 24.3 | 24.5 | 24.7 | 24.8 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 21.6 | 21.7 | 22.2 | 22.8 | 23.1 | 23.4 | 23.6 | 24.2 | 24.4 | 24.3 | 24.5 | 24.7 | 24.8 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:OffNetServices srt:NorthAmerica | 100.0 | 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 | 2019-12-31 | 2019-09-30 |
| Value | 0.014 | 0.014 | 0.007 | 0.005 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:OffNetServices srt:SouthAmerica | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 0.092 | 0.078 | 0.062 | 0.01 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.1 | 0.1 | 0.0 | 0.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.1 | 0.1 | 0.0 | 0.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:OnNetServices srt:Africa | 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 |
| Value | 2.449 | 2.173 | 1.954 | 1.786 | 0.426 | 1.471 | 1.315 | 1.18 | 1.128 | 0.991 | 0.876 | 0.676 | 0.556 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 1.7 | 1.5 | 1.4 | 1.3 | 0.3 | 1.0 | 0.9 | 0.9 | 0.8 | 0.7 | 0.7 | 0.5 | 0.4 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 1.7 | 1.5 | 1.4 | 1.3 | 0.3 | 1.0 | 0.9 | 0.9 | 0.8 | 0.7 | 0.7 | 0.5 | 0.4 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:OnNetServices srt:AsiaPacific | 100.0 | 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 |
| Value | 22 | 22 | 21 | 19 | 19 | 19 | 18 | 17 | 17 | 18 | 17 | 17 | 18 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 15.1 | 15.3 | 14.7 | 14.0 | 13.7 | 13.6 | 13.1 | 13.1 | 13.2 | 13.6 | 13.5 | 13.7 | 14.2 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 15.1 | 15.3 | 14.7 | 14.0 | 13.7 | 13.6 | 13.1 | 13.1 | 13.2 | 13.6 | 13.5 | 13.7 | 14.2 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:OnNetServices srt:Europe | 100.0 | 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 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 1.005 | 0.812 | 1.624 | 0.32 | 0.244 | 0.139 | 0.071 | 0.034 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.7 | 0.6 | 1.2 | 0.2 | 0.2 | 0.1 | 0.1 | 0.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.7 | 0.6 | 1.2 | 0.2 | 0.2 | 0.1 | 0.1 | 0.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:OnNetServices srt:LatinAmerica | 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 |
| Value | 85 | 84 | 83 | 82 | 82 | 82 | 82 | 80 | 78 | 77 | 76 | 75 | 74 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 57.6 | 57.5 | 57.9 | 58.1 | 58.4 | 58.6 | 58.9 | 58.5 | 58.2 | 58.1 | 58.0 | 57.8 | 57.3 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 57.6 | 57.5 | 57.9 | 58.1 | 58.4 | 58.6 | 58.9 | 58.5 | 58.2 | 58.1 | 58.0 | 57.8 | 57.3 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:OnNetServices srt:NorthAmerica | 100.0 | 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 | 2019-12-31 | 2019-09-30 |
| Value | 0.712 | 0.599 | 0.244 | 0.139 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.5 | 0.4 | 0.2 | 0.1 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.5 | 0.4 | 0.2 | 0.1 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:OnNetServices srt:SouthAmerica | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 0.093 | 0.079 | 0.062 | 0.01 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.1 | 0.1 | 0.0 | 0.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.1 | 0.1 | 0.0 | 0.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax srt:Africa | 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 |
| Value | 2.712 | 2.444 | 2.211 | 2.026 | 0.436 | 1.697 | 1.511 | 1.368 | 1.339 | 1.173 | 1.043 | 0.822 | 0.693 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 1.8 | 1.7 | 1.5 | 1.4 | 0.3 | 1.2 | 1.1 | 1.0 | 1.0 | 0.9 | 0.8 | 0.6 | 0.5 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 1.8 | 1.7 | 1.5 | 1.4 | 0.3 | 1.2 | 1.1 | 1.0 | 1.0 | 0.9 | 0.8 | 0.6 | 0.5 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax srt:AsiaPacific | 100.0 | 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 |
| Value | 26 | 27 | 25 | 24 | 23 | 23 | 22 | 21 | 21 | 22 | 21 | 21 | 22 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 18.2 | 18.4 | 17.8 | 17.1 | 16.7 | 16.5 | 16.1 | 16.0 | 16.3 | 16.6 | 16.6 | 16.8 | 17.3 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 18.2 | 18.4 | 17.8 | 17.1 | 16.7 | 16.5 | 16.1 | 16.0 | 16.3 | 16.6 | 16.6 | 16.8 | 17.3 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax srt:Europe | 100.0 | 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 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 1.054 | 0.828 | 1.85 | 0.331 | 0.251 | 0.144 | 0.074 | 0.034 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.7 | 0.6 | 1.3 | 0.2 | 0.2 | 0.1 | 0.1 | 0.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.7 | 0.6 | 1.3 | 0.2 | 0.2 | 0.1 | 0.1 | 0.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax srt:LatinAmerica | 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 |
| Value | 117 | 116 | 115 | 115 | 115 | 115 | 115 | 113 | 111 | 110 | 109 | 107 | 106 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 79.2 | 79.3 | 80.1 | 81.0 | 81.7 | 82.0 | 82.7 | 82.8 | 82.7 | 82.5 | 82.6 | 82.6 | 82.2 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 79.2 | 79.3 | 80.1 | 81.0 | 81.7 | 82.0 | 82.7 | 82.8 | 82.7 | 82.5 | 82.6 | 82.6 | 82.2 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax srt:NorthAmerica | 100.0 | 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 | 2019-12-31 | 2019-09-30 |
| Value | 0.726 | 0.613 | 0.251 | 0.144 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.5 | 0.4 | 0.2 | 0.1 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 0.5 | 0.4 | 0.2 | 0.1 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax srt:SouthAmerica | 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 | 143 | 142 | 140 | 140 | 140 | 136 | 134 | 134 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax ccoi:Unaudited | 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 | 41 | 41 | 39 | 39 | 39 | 39 | 36 | 35 | 38 | 35 | 33 | 33 | 33 | 33 | 31 | 32 | 31 | 31 | 31 | 30 | 29 | 29 | 27 | 27 | 28 | 29 | 27 | 27 | 26 | 26 | 22 | 21 | 21 | 21 | 19 | 19 | 19 | 21 | 19 | 18 | 18 | 19 | 17 | 17 | 18 |
| 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 RevenueFromContractWithCustomerIncludingAssessedTax | 28.0 | 28.2 | 27.3 | 27.9 | 28.3 | 28.2 | 26.0 | 26.3 | 28.6 | 26.7 | 25.2 | 25.7 | 26.1 | 26.0 | 25.4 | 26.8 | 26.5 | 26.8 | 29.8 | 29.2 | 30.2 | 30.4 | 25.8 | 26.5 | 29.3 | 30.5 | 28.8 | 28.6 | 27.6 | 28.3 | 25.4 | 24.7 | 24.7 | 25.4 | 23.8 | 24.4 | 24.9 | 27.8 | 24.7 | 24.5 | 25.0 | 26.6 | 25.6 | 26.4 | 28.1 |
| 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 | 2010-12-31 |
| Value | 1010 | 852 | 1000 | 1000 | 1005 | 913 | 932 | 932 | 949 | 797 | 739 | 757 | 700 | 716 | 710 | 729 | 732 | 732 | 737 | 617 | 626 | 665 | 662 | 672 | 682 | 714 | 761 | 784 | 822 | 725 | 755 | 692 | 621 | 616 | 606 | 592 | 595 | 597 | 597 | 578 | 587 | 376 |
| 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 | 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 | 1346 | 1160 | 1293 | 1261 | 1240 | 1135 | 1135 | 1122 | 1125 | 961 | 888 | 883 | 814 | 813 | 813 | 809 | 803 | 796 | 791 | 658 | 655 | 683 | 675 | 671 | 660 | 659 | 677 | 675 | 682 | 562 | 561 | 537 | 466 | 460 | 446 | 431 | 434 | 432 | 433 | 419 | 425 | 224 |
| 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 | 133.3 | 136.1 | 129.3 | 126.0 | 123.4 | 124.3 | 121.9 | 120.4 | 118.6 | 120.6 | 120.1 | 116.6 | 116.4 | 113.5 | 114.4 | 111.0 | 109.7 | 108.7 | 107.2 | 106.6 | 104.7 | 102.8 | 101.9 | 99.8 | 96.7 | 92.4 | 89.0 | 86.1 | 82.9 | 77.5 | 74.4 | 77.6 | 75.1 | 74.7 | 73.7 | 72.8 | 72.9 | 72.4 | 72.6 | 72.6 | 72.4 | 59.6 |
| 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 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 1010 | 852 | 1000 | 1000 | 1005 | 913 | 932 | 932 | 949 | 797 | 739 | 757 | 700 | 716 | 710 | 729 | 732 | 732 | 737 | 617 | 626 | 665 | 662 | 672 | 682 | 714 | 761 | 784 | 822 | 725 | 755 | 692 | 621 | 616 | 606 | 592 | 595 | 597 | 597 | 578 | 587 | 376 |
| 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 | 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 | 2010-12-31 | 2009-12-31 | 2008-12-31 |
| Value | -336.141 | -307.559 | -293.166 | -260.691 | -235.55 | -222.225 | -203.679 | -190.501 | -176.59 | -164.231 | -149.002 | -125.844 | -114.636 | -97.055 | -102.544 | -80.123 | -71.201 | -63.612 | -53.254 | -40.486 | -29.389 | -18.382 | -12.271 | 1.102 | 22 | 54 | 83 | 108 | 140 | 163 | 193 | 155 | 154 | 155 | 159 | 160 | 161 | 164 | 164 | 158 | 151 | 144 | 150 |
| 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 | 100.0 |
| Percentage of Assets | -33.3 | -36.1 | -29.3 | -26.0 | -23.4 | -24.3 | -21.9 | -20.4 | -18.6 | -20.6 | -20.1 | -16.6 | -16.4 | -13.5 | -14.4 | -11.0 | -9.7 | -8.7 | -7.2 | -6.6 | -4.7 | -2.8 | -1.9 | 0.2 | 3.3 | 7.6 | 11.0 | 13.9 | 17.1 | 22.5 | 25.6 | 22.4 | 24.9 | 25.3 | 26.3 | 27.2 | 27.1 | 27.6 | 27.4 | 27.4 | 40.4 | 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 | 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 | -4.74 | -6.516 | -1.306 | -7.498 | -12.906 | -15.819 | -12.326 | -15.676 | -10.967 | -12.753 | -10.928 | -8.672 | -8.187 | -1.989 | -4.6 | -17.193 | -14.693 | -6.462 | 2.136 | 0.667 | -0.582 | 1.044 | 1.976 | 0.572 |
| Percentage of StockholdersEquity | 1.4 | 2.1 | 0.4 | 2.9 | 5.5 | 7.1 | 6.1 | 8.2 | 6.2 | 7.8 | 7.3 | 6.9 | 7.1 | 2.0 | 4.5 | 32.3 | 119.7 | -7.7 | 1.1 | 0.4 | -0.4 | 0.7 | 1.4 | 0.4 |
| Percentage of Assets | -0.5 | -0.8 | -0.1 | -0.7 | -1.3 | -1.7 | -1.3 | -1.7 | -1.2 | -1.6 | -1.5 | -1.1 | -1.2 | -0.3 | -0.6 | -2.3 | -2.2 | -0.8 | 0.3 | 0.1 | -0.1 | 0.3 | 0.0 | 0.0 |
| Percentage of Assets us-gaap:AccumulatedTranslationAdjustment | 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 | 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 | 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 | 533 | 523 | 515 | 513 | 506 | 499 | 493 | 487 | 481 | 475 | 471 | 472 | 467 | 461 | 456 | 442 | 434 | 460 | 508 | 497 | 489 | 482 | 475 | 465 |
| Percentage of StockholdersEquity | -158.6 | -170.3 | -176.0 | -197.0 | -215.0 | -224.8 | -242.1 | -255.8 | -272.8 | -289.4 | -316.3 | -375.7 | -407.4 | -475.1 | -445.4 | -831.5 | -3538.1 | 549.7 | 262.7 | 311.3 | 298.2 | 318.0 | 328.9 | 308.1 |
| Percentage of Assets | 52.7 | 61.4 | 51.6 | 51.3 | 50.4 | 54.7 | 52.9 | 52.3 | 50.8 | 59.6 | 63.7 | 62.4 | 66.7 | 64.4 | 64.3 | 60.0 | 65.5 | 60.5 | 67.3 | 82.0 | 81.8 | 128.4 | 0.0 | 0.0 |
| Percentage of Assets us-gaap:AdditionalPaidInCapital | 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 | 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 | 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 | 0.048 | 0.048 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | 0.045 | 0.045 | 0.046 | 0.047 | 0.047 | 0.046 | 0.046 | 0.045 | 0.044 |
| Percentage of StockholdersEquity | -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 | -0.1 | -0.4 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Assets | 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 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| 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 | 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 | 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 | -864.498 | -825.004 | -807.774 | -766.694 | -729.082 | -705.908 | -684.578 | -662.268 | -647.404 | -626.799 | -609.451 | -590.035 | -573.502 | -556.266 | -554.686 | -478.905 | -431.784 | -370.366 | -316.947 | -338.284 | -324.484 | -332.026 | -332.695 | -315.544 |
| Percentage of StockholdersEquity | 257.2 | 268.2 | 275.5 | 294.1 | 309.5 | 317.7 | 336.1 | 347.6 | 366.6 | 381.7 | 409.0 | 468.9 | 500.3 | 573.1 | 540.9 | 899.3 | 3518.7 | -442.0 | -163.8 | -211.7 | -197.9 | -218.7 | -230.3 | -209.0 |
| Percentage of Assets | -85.5 | -96.7 | -80.7 | -76.6 | -72.5 | -77.3 | -73.4 | -71.0 | -68.2 | -78.6 | -82.4 | -77.9 | -81.9 | -77.6 | -78.1 | -64.9 | -65.1 | -48.6 | -42.0 | -55.8 | -54.3 | -88.3 | 0.0 | 0.0 |
| 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 | 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 | 454 | 316 | 456 | 475 | 497 | 456 | 475 | 474 | 485 | 333 | 350 | 358 | 296 | 307 | 306 | 310 | 313 | 317 | 327 | 202 | 208 | 247 | 251 | 260 | 276 | 311 | 339 | 364 | 405 | 320 | 354 | 346 | 278 | 274 | 281 | 271 | 274 | 269 | 273 | 258 | 264 | 88 |
| 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 | 45.0 | 37.1 | 45.6 | 47.5 | 49.4 | 50.0 | 51.0 | 50.9 | 51.2 | 41.9 | 47.4 | 47.3 | 42.4 | 42.9 | 43.1 | 42.5 | 42.8 | 43.4 | 44.4 | 32.8 | 33.2 | 37.2 | 37.9 | 38.6 | 40.5 | 43.7 | 44.6 | 46.4 | 49.3 | 44.2 | 46.9 | 50.0 | 44.9 | 44.5 | 46.4 | 45.7 | 46.2 | 45.1 | 45.7 | 44.7 | 45.0 | 23.6 |
| 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 | 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 | 373 | 237 | 371 | 393 | 417 | 375 | 399 | 396 | 409 | 259 | 276 | 284 | 224 | 236 | 247 | 250 | 256 | 263 | 274 | 148 | 154 | 196 | 203 | 207 | 224 | 260 | 287 | 311 | 349 | 263 | 304 | 304 | 237 | 234 | 247 | 232 | 237 | 232 | 238 | 224 | 227 | 225 | 56 | 47 | 52 | 55 | 71 |
| 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 | 37.0 | 27.9 | 37.1 | 39.3 | 41.5 | 41.1 | 42.9 | 42.5 | 43.1 | 32.5 | 37.3 | 37.6 | 32.0 | 32.9 | 34.8 | 34.4 | 35.0 | 35.9 | 37.2 | 24.0 | 24.7 | 29.5 | 30.7 | 30.8 | 32.9 | 36.4 | 37.8 | 39.7 | 42.5 | 36.4 | 40.4 | 44.0 | 38.2 | 38.1 | 40.8 | 39.1 | 39.9 | 38.9 | 39.9 | 38.8 | 38.7 | 0.0 | 15.0 | 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 | 43 | 41 | 44 | 42 | 40 | 42 | 40 | 41 | 40 | 39 | 41 | 40 | 39 | 38 | 39 | 39 | 34 | 33 | 33 | 33 | 32 | 31 | 30 | 30 | 30 | 29 | 33 | 31 | 33 | 33 | 30 | 28 | 27 | 26 | 23 | 27 | 25 | 24 | 25 | 24 | 26 | 23 |
| 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 | 4.3 | 4.8 | 4.4 | 4.2 | 4.0 | 4.7 | 4.3 | 4.4 | 4.3 | 4.9 | 5.6 | 5.4 | 5.6 | 5.3 | 5.5 | 5.4 | 4.7 | 4.6 | 4.6 | 5.4 | 5.2 | 4.7 | 4.6 | 4.6 | 4.5 | 4.2 | 4.3 | 4.0 | 4.1 | 4.6 | 4.1 | 4.1 | 4.4 | 4.4 | 4.0 | 4.7 | 4.3 | 4.2 | 4.2 | 4.3 | 4.5 | 6.3 |
| 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 | 36 | 37 | 40 | 40 | 39 | 38 | 35 | 36 | 36 | 35 | 32 | 32 | 32 | 33 | 20 | 20 | 21 | 20 | 19 | 20 | 20 | 19 | 17 | 21 | 21 | 22 | 18 | 20 | 22 | 23 | 18 | 12 | 14 | 12 | 9.978 | 11 | 11 | 12 | 10 | 9.863 | 11 | 8.654 |
| Percentage of PrepaidExpenseAndOtherAssetsCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 3.6 | 4.3 | 4.1 | 4.0 | 3.9 | 4.2 | 3.8 | 3.9 | 3.8 | 4.4 | 4.4 | 4.4 | 4.7 | 4.7 | 2.8 | 2.8 | 3.0 | 2.9 | 2.7 | 3.3 | 3.3 | 3.0 | 2.6 | 3.2 | 3.1 | 3.1 | 2.5 | 2.6 | 2.7 | 3.3 | 2.5 | 1.9 | 2.3 | 2.0 | 1.6 | 1.9 | 2.0 | 2.1 | 1.7 | 1.7 | 1.9 | 2.3 |
| 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 | 2011-03-31 | 2010-12-31 |
| Value | 436 | 425 | 430 | 421 | 406 | 367 | 368 | 370 | 375 | 375 | 375 | 380 | 382 | 385 | 381 | 381 | 376 | 368 | 361 | 370 | 370 | 366 | 360 | 357 | 347 | 343 | 360 | 357 | 353 | 346 | 341 | 331 | 328 | 328 | 311 | 306 | 304 | 311 | 308 | 308 | 280 |
| Percentage of NoncurrentAssets | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 43.1 | 49.9 | 43.0 | 42.1 | 40.5 | 40.2 | 39.6 | 39.8 | 39.6 | 47.1 | 50.7 | 50.3 | 54.6 | 53.8 | 53.7 | 52.2 | 51.5 | 50.4 | 49.0 | 60.0 | 59.2 | 55.1 | 54.3 | 53.1 | 50.9 | 48.1 | 47.4 | 45.6 | 43.0 | 47.7 | 45.2 | 47.9 | 52.9 | 53.2 | 51.3 | 51.7 | 51.2 | 52.1 | 51.5 | 0.0 | 74.6 |
| 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 | 2017-12-31 |
| Value | 127 | 123 | 123 | 115 | 105 | 100 | 99 | 97 | 102 | 99 | 99 | 99 |
| Percentage of NoncurrentAssets | 29.2 | 29.0 | 28.7 | 27.4 | 26.0 | 27.3 | 27.0 | 26.2 | 27.2 | 26.5 | 26.6 | 26.0 |
| Percentage of Assets | 12.6 | 14.5 | 12.4 | 11.6 | 10.5 | 11.0 | 10.7 | 10.4 | 10.8 | 12.5 | 13.5 | 14.0 |
| Percentage of Assets ccoi:EuropeAndOther | 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 | 2018-12-31 |
| Value | 308 | 302 | 306 | 305 | 301 | 267 | 269 | 273 | 273 | 275 |
| Percentage of NoncurrentAssets | 70.8 | 71.0 | 71.3 | 72.6 | 74.0 | 72.7 | 73.0 | 73.8 | 72.8 | 73.4 |
| Percentage of Assets | 30.5 | 35.4 | 30.7 | 30.5 | 30.0 | 29.2 | 28.9 | 29.3 | 28.8 | 37.2 |
| Percentage of Assets srt:NorthAmerica | 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 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 |
| Value | 1515 | 421 | 406 | 367 | 1366 | 1300 | 1233 | 1136 | 1070 | 1047 | 985 | 889 | 836 | 759 |
| Percentage of PropertyPlantAndEquipmentGross | 100.0 | 100.0 | 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 | 151.5 | 42.1 | 40.5 | 40.2 | 146.6 | 175.8 | 173.6 | 154.0 | 161.4 | 137.5 | 130.5 | 146.6 | 139.9 | 202.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 |
| Value | 1032 | 958 | 905 | 850 | 786 |
| Percentage of PropertyPlantAndEquipmentGross | 68.1 | 70.1 | 69.6 | 68.9 | 69.2 |
| Percentage of Assets | 103.2 | 102.8 | 122.4 | 119.7 | 106.6 |
| Percentage of Assets us-gaap:Assets | 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 |
| Value | 1.376 | 1.252 | 1.277 | 1.334 | 1.171 |
| Percentage of PropertyPlantAndEquipmentGross | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 |
| Percentage of Assets | 0.1 | 0.1 | 0.2 | 0.2 | 0.2 |
| Percentage of Assets us-gaap:Assets us-gaap:Building | 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 |
| Value | 611 | 566 | 538 | 510 | 476 |
| Percentage of PropertyPlantAndEquipmentGross | 40.3 | 41.5 | 41.4 | 41.4 | 42.0 |
| Percentage of Assets | 61.1 | 60.8 | 72.8 | 71.8 | 64.6 |
| Percentage of Assets us-gaap:Assets us-gaap:Equipment | 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 |
| Value | 0.116 | 0.106 | 0.108 | 0.113 | 0.099 |
| Percentage of PropertyPlantAndEquipmentGross | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Assets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Assets us-gaap:Assets us-gaap:Land | 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 |
| Value | 241 | 227 | 214 | 200 | 182 |
| Percentage of PropertyPlantAndEquipmentGross | 15.9 | 16.6 | 16.5 | 16.2 | 16.1 |
| Percentage of Assets | 24.1 | 24.4 | 29.0 | 28.2 | 24.8 |
| Percentage of Assets us-gaap:Assets us-gaap:LeaseholdImprovements | 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 |
| Value | 19 | 18 | 16 | 14 | 13 |
| Percentage of PropertyPlantAndEquipmentGross | 1.3 | 1.3 | 1.3 | 1.2 | 1.2 |
| Percentage of Assets | 2.0 | 1.9 | 2.3 | 2.1 | 1.9 |
| Percentage of Assets us-gaap:Assets us-gaap:OfficeEquipment | 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 |
| Value | 10 | 10 | 9.963 | 9.701 | 9.523 |
| Percentage of PropertyPlantAndEquipmentGross | 0.7 | 0.7 | 0.8 | 0.8 | 0.8 |
| Percentage of Assets | 1.1 | 1.1 | 1.3 | 1.4 | 1.3 |
| Percentage of Assets us-gaap:Assets us-gaap:SoftwareAndSoftwareDevelopmentCosts | 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 |
| Value | 148 | 134 | 124 | 114 | 102 |
| Percentage of PropertyPlantAndEquipmentGross | 9.8 | 9.9 | 9.5 | 9.2 | 9.0 |
| Percentage of Assets | 14.8 | 14.5 | 16.8 | 16.0 | 13.9 |
| Percentage of Assets us-gaap:Assets us-gaap:TechnologyEquipment | 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 | 482 | 408 | 395 | 383 |
| Percentage of PropertyPlantAndEquipmentGross | 31.9 | 29.9 | 30.4 | 31.1 |
| Percentage of Assets | 48.3 | 43.8 | 53.4 | 54.0 |
| Percentage of Assets us-gaap:ContractualRights | 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 | 2010-12-31 |
| Value | 1085 | 997 | 925 | 852 | 774 | 709 | 686 | 643 | 578 | 528 | 479 |
| Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment | 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 | 108.5 | 107.1 | 125.0 | 120.0 | 105.0 | 107.1 | 90.2 | 85.3 | 95.3 | 88.4 | 127.5 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 |
| Value | 856 | 790 | 736 | 680 | 621 |
| Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment | 78.9 | 79.2 | 79.6 | 79.8 | 80.2 |
| Percentage of Assets | 85.6 | 84.8 | 99.5 | 95.7 | 84.2 |
| Percentage of Assets us-gaap:Assets | 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 | 228 | 207 | 188 | 172 |
| Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment | 21.1 | 20.8 | 20.4 | 20.2 |
| Percentage of Assets | 22.9 | 22.3 | 25.5 | 24.3 |
| Percentage of Assets us-gaap:ContractualRights | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 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 | 435 | 425 | 430 | 368 | 370 | 375 | 375 | 375 | 381 | 382 | 385 | 381 | 381 | 376 | 368 | 361 | 370 | 370 | 366 | 360 | 357 | 347 | 343 | 360 | 357 | 353 | 346 | 341 | 331 | 328 | 328 | 311 | 306 | 304 | 311 | 307 | 308 | 312 | 280 |
| 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 |
| Percentage of Assets | 43.1 | 49.9 | 43.0 | 39.6 | 39.8 | 39.6 | 47.1 | 50.7 | 50.3 | 54.7 | 53.8 | 53.7 | 52.2 | 51.5 | 50.4 | 49.0 | 60.0 | 59.2 | 55.1 | 54.3 | 53.1 | 50.9 | 48.1 | 47.4 | 45.6 | 43.0 | 47.7 | 45.2 | 47.9 | 52.9 | 53.2 | 51.3 | 51.7 | 51.2 | 52.1 | 51.5 | 53.4 | 53.1 | 74.6 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 |
| Value | 176 | 168 | 168 | 170 | 165 |
| Percentage of PropertyPlantAndEquipmentNet | 40.9 | 45.7 | 45.0 | 44.6 | 45.7 |
| Percentage of Assets | 17.6 | 18.1 | 22.8 | 23.9 | 22.4 |
| Percentage of Assets us-gaap:Assets | 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 | 254 | 200 | 206 | 211 |
| Percentage of PropertyPlantAndEquipmentNet | 59.1 | 54.3 | 55.0 | 55.4 |
| Percentage of Assets | 25.4 | 21.5 | 27.9 | 29.7 |
| Percentage of Assets us-gaap:ContractualRights | 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 | 2010-12-31 |
| Value | 170 | 162 | 2.733 | 17 | 42 | 45 | 52 | 56 | 6.186 | 8.784 | 3.065 |
| Percentage of DeferredTaxAssetsLiabilitiesNet | 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 | 17.0 | 17.5 | 0.4 | 2.5 | 5.7 | 6.8 | 7.0 | 7.4 | 1.0 | 1.5 | 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 | 14 | 12 | 9.775 | 11 | 12 | 13 | 11 | 9.849 | 11 | 9.619 | 8.519 | 8.262 | 10 | 12 | 11 | 12 | 9.284 | 12 | 11 | 13 | 16 | 19 | 12 | 15 | 15 | 16 | 13 | 16 | 16 | 16 | 14 | 12 | 15 | 16 | 14 | 13 | 11 | 15 | 14 | 9.971 | 10 | 15 |
| 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 | 1.4 | 1.4 | 1.0 | 1.2 | 1.2 | 1.4 | 1.2 | 1.1 | 1.2 | 1.2 | 1.2 | 1.1 | 1.5 | 1.8 | 1.6 | 1.7 | 1.3 | 1.7 | 1.6 | 2.1 | 2.6 | 2.9 | 1.9 | 2.3 | 2.3 | 2.3 | 1.7 | 2.1 | 2.1 | 2.3 | 1.9 | 1.8 | 2.6 | 2.7 | 2.4 | 2.3 | 1.9 | 2.6 | 2.4 | 1.7 | 1.9 | 4.2 |
| 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 | 48 | 49 | 51 | 47 | 52 | 49 | 51 | 49 | 51 | 45 | 51 | 46 | 47 | 46 | 47 | 47 | 49 | 45 | 47 | 41 | 43 | 40 | 38 | 45 | 40 | 38 | 32 | 31 | 34 | 27 | 31 | 23 | 27 | 24 | 26 | 20 | 25 | 20 | 21 | 19 | 23 | 19 |
| Percentage of AccruedLiabilitiesCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 4.8 | 5.8 | 5.1 | 4.8 | 5.2 | 5.4 | 5.5 | 5.3 | 5.4 | 5.7 | 7.0 | 6.2 | 6.8 | 6.4 | 6.7 | 6.5 | 6.7 | 6.2 | 6.4 | 6.8 | 6.9 | 6.1 | 5.8 | 6.8 | 6.0 | 5.4 | 4.2 | 4.0 | 4.2 | 3.8 | 4.2 | 3.5 | 4.4 | 4.0 | 4.4 | 3.5 | 4.3 | 3.4 | 3.7 | 3.3 | 4.1 | 5.2 |
| 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 | 93 | 422 | 94 | 95 | 100 | 90 | 89 | 86 | 90 | 81 | 75 | 72 | 74 | 74 | 74 | 73 | 72 | 69 | 67 | 61 | 65 | 78 | 68 | 68 | 64 | 68 | 60 | 56 | 60 | 142 | 143 | 131 | 136 | 47 | 51 | 42 | 45 | 45 | 47 | 39 | 43 | 41 |
| 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 | 9.3 | 49.6 | 9.4 | 9.5 | 10.0 | 9.9 | 9.6 | 9.2 | 9.5 | 10.2 | 10.2 | 9.5 | 10.7 | 10.4 | 10.5 | 10.1 | 9.9 | 9.5 | 9.2 | 10.0 | 10.5 | 11.9 | 10.4 | 10.2 | 9.5 | 9.6 | 7.9 | 7.2 | 7.3 | 19.6 | 19.0 | 19.1 | 21.9 | 7.7 | 8.5 | 7.1 | 7.7 | 7.6 | 8.0 | 6.8 | 7.3 | 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 |
| Value | 11 | 11 | 11 | 12 | 11 | 10 | 10 | 10 | 10 | 10 |
| Percentage of OperatingLeaseLiabilityCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 1.2 | 1.3 | 1.1 | 1.2 | 1.1 | 1.1 | 1.1 | 1.1 | 1.1 | 1.3 |
| 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 | 24 | 23 | 24 | 25 | 47 | 38 | 32 | 31 | 26 | 21 |
| Percentage of OtherAccruedLiabilitiesCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 2.4 | 2.5 | 3.2 | 3.6 | 6.4 | 5.8 | 4.2 | 4.2 | 4.4 | 3.7 |
| Period End | 2020-12-31 |
| Value | 881 |
| Percentage of LongTermDebt | 100.0 |
| Percentage of Assets | 88.2 |
| Period End | 2021-05-31 |
| Value | 284 |
| Percentage of LongTermDebt | 0.0 |
| Percentage of Assets | 0.0 |
| Percentage of Assets ccoi:SeniorSecuredNotesDue2022 | 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 |
| Value | 412 | 406 | 425 | 406 | 388 | 147 | 150 | 145 |
| Percentage of UnsecuredLongTermDebt | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 40.8 | 47.7 | 42.5 | 40.6 | 38.6 | 16.1 | 16.1 | 15.6 |
| Percentage of Assets ccoi:SeniorUnsecuredNotesOf4.375Due2024 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 |
| Value | 444 |
| Percentage of UnsecuredLongTermDebt | 104.5 |
| Percentage of Assets | 44.4 |
| Percentage of Assets us-gaap:SecuredDebt | 0.0 |
| Period End | 2021-06-30 |
| Value | 497 |
| Percentage of SecuredLongTermDebt | 100.0 |
| Percentage of Assets | 49.2 |
| Percentage of Assets ccoi:SeniorSecuredNotesDue2026 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2018-12-31 |
| Value | 444 | 444 | 444 | 444 | 443 |
| Percentage of SecuredLongTermDebt | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Assets | 44.4 | 44.4 | 44.2 | 47.6 | 60.0 |
| Percentage of Assets us-gaap:SecuredDebt | 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 | 19 | 19 | 14 | 16 | 19 | 17 | 15 | 13 | 7.588 | 5.795 | 25 | 26 | 27 | 27 | 27 | 28 | 28 | 29 | 28 | 26 | 24 | 27 | 30 | 29 | 25 | 22 | 21 | 21 | 21 | 20 | 19 | 10 | 10 | 10 | 10 | 9.913 | 11 | 10 | 11 | 6.056 | 6.232 | 5.86 |
| 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 | 2.3 | 1.5 | 1.7 | 2.0 | 1.9 | 1.6 | 1.4 | 0.8 | 0.7 | 3.4 | 3.5 | 3.9 | 3.8 | 3.9 | 3.9 | 3.9 | 4.0 | 3.8 | 4.3 | 3.9 | 4.1 | 4.7 | 4.5 | 3.7 | 3.2 | 2.9 | 2.7 | 2.6 | 2.8 | 2.6 | 1.6 | 1.7 | 1.7 | 1.7 | 1.7 | 1.9 | 1.7 | 1.9 | 1.0 | 1.1 | 1.6 |
| 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 |
| Value | 115 | 109 | 111 | 101 | 99 | 88 | 86 | 85 | 83 | 84 |
| Percentage of OperatingLeaseLiabilityNoncurrent | 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 | 12.8 | 11.1 | 10.1 | 9.9 | 9.7 | 9.3 | 9.2 | 8.8 | 10.6 |
| Period End | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 120 | 122 | 113 |
| Percentage of OperatingLeaseLiability | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 14.1 | 12.2 | 11.3 |
| Period End | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 191 | 196 | 179 |
| Percentage of LesseeOperatingLeaseLiabilityPaymentsDue | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 22.5 | 19.6 | 18.0 |
| Period End | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 71 | 73 | 66 |
| Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 8.3 | 7.4 | 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 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2010-12-31 | 2009-12-31 | 2008-12-31 |
| Value | -336.141 | -307.559 | -293.166 | -260.691 | -235.55 | -222.225 | -203.679 | -190.501 | -176.59 | -164.231 | -149.002 | -125.844 | -114.636 | -97.055 | -102.544 | -80.123 | -71.201 | -63.612 | -53.254 | -40.486 | -29.389 | -18.382 | -12.271 | 1.102 | 22 | 54 | 83 | 108 | 140 | 163 | 193 | 155 | 154 | 155 | 159 | 160 | 161 | 164 | 164 | 158 | 151 | 144 | 150 |
| 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 | 100.0 |
| Percentage of Assets | -33.3 | -36.1 | -29.3 | -26.0 | -23.4 | -24.3 | -21.9 | -20.4 | -18.6 | -20.6 | -20.1 | -16.6 | -16.4 | -13.5 | -14.4 | -11.0 | -9.7 | -8.7 | -7.2 | -6.6 | -4.7 | -2.8 | -1.9 | 0.2 | 3.3 | 7.6 | 11.0 | 13.9 | 17.1 | 22.5 | 25.6 | 22.4 | 24.9 | 25.3 | 26.3 | 27.2 | 27.1 | 27.6 | 27.4 | 27.4 | 40.4 | 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 | 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 | -4.74 | -6.516 | -1.306 | -7.498 | -12.906 | -15.819 | -12.326 | -15.676 | -10.967 | -12.753 | -10.928 | -8.672 | -8.187 | -1.989 | -4.6 | -17.193 | -14.693 | -6.462 | 2.136 | 0.667 | -0.582 | 1.044 | 1.976 | 0.572 |
| Percentage of StockholdersEquity | 1.4 | 2.1 | 0.4 | 2.9 | 5.5 | 7.1 | 6.1 | 8.2 | 6.2 | 7.8 | 7.3 | 6.9 | 7.1 | 2.0 | 4.5 | 32.3 | 119.7 | -7.7 | 1.1 | 0.4 | -0.4 | 0.7 | 1.4 | 0.4 |
| Percentage of Assets | -0.5 | -0.8 | -0.1 | -0.7 | -1.3 | -1.7 | -1.3 | -1.7 | -1.2 | -1.6 | -1.5 | -1.1 | -1.2 | -0.3 | -0.6 | -2.3 | -2.2 | -0.8 | 0.3 | 0.1 | -0.1 | 0.3 | 0.0 | 0.0 |
| Percentage of Assets us-gaap:AccumulatedTranslationAdjustment | 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 | 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 | 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 | 533 | 523 | 515 | 513 | 506 | 499 | 493 | 487 | 481 | 475 | 471 | 472 | 467 | 461 | 456 | 442 | 434 | 460 | 508 | 497 | 489 | 482 | 475 | 465 |
| Percentage of StockholdersEquity | -158.6 | -170.3 | -176.0 | -197.0 | -215.0 | -224.8 | -242.1 | -255.8 | -272.8 | -289.4 | -316.3 | -375.7 | -407.4 | -475.1 | -445.4 | -831.5 | -3538.1 | 549.7 | 262.7 | 311.3 | 298.2 | 318.0 | 328.9 | 308.1 |
| Percentage of Assets | 52.7 | 61.4 | 51.6 | 51.3 | 50.4 | 54.7 | 52.9 | 52.3 | 50.8 | 59.6 | 63.7 | 62.4 | 66.7 | 64.4 | 64.3 | 60.0 | 65.5 | 60.5 | 67.3 | 82.0 | 81.8 | 128.4 | 0.0 | 0.0 |
| Percentage of Assets us-gaap:AdditionalPaidInCapital | 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 | 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 | 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 | 0.048 | 0.048 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.047 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | 0.046 | 0.045 | 0.045 | 0.046 | 0.047 | 0.047 | 0.046 | 0.046 | 0.045 | 0.044 |
| Percentage of StockholdersEquity | -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 | -0.1 | -0.4 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Assets | 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 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| 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 | 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 | 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 | -864.498 | -825.004 | -807.774 | -766.694 | -729.082 | -705.908 | -684.578 | -662.268 | -647.404 | -626.799 | -609.451 | -590.035 | -573.502 | -556.266 | -554.686 | -478.905 | -431.784 | -370.366 | -316.947 | -338.284 | -324.484 | -332.026 | -332.695 | -315.544 |
| Percentage of StockholdersEquity | 257.2 | 268.2 | 275.5 | 294.1 | 309.5 | 317.7 | 336.1 | 347.6 | 366.6 | 381.7 | 409.0 | 468.9 | 500.3 | 573.1 | 540.9 | 899.3 | 3518.7 | -442.0 | -163.8 | -211.7 | -197.9 | -218.7 | -230.3 | -209.0 |
| Percentage of Assets | -85.5 | -96.7 | -80.7 | -76.6 | -72.5 | -77.3 | -73.4 | -71.0 | -68.2 | -78.6 | -82.4 | -77.9 | -81.9 | -77.6 | -78.1 | -64.9 | -65.1 | -48.6 | -42.0 | -55.8 | -54.3 | -88.3 | 0.0 | 0.0 |
| 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 | 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 | 48000.0 | 48000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 | 45000.0 | 45000.0 | 45000.0 | 45000.0 | 45000.0 | 45000.0 | 45000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 47000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 | 46000.0 |
| Percentage of CommonStockValue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 0.0 | 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 | 0.0 | 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 | 0.0 | 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 | 533 | 523 | 515 | 513 | 506 | 499 | 493 | 487 | 481 | 475 | 471 | 472 | 467 | 461 | 456 | 452 | 447 | 445 | 442 | 442 | 440 | 436 | 434 | 431 | 440 | 456 | 460 | 467 | 480 | 496 | 508 | 505 | 503 | 500 | 497 | 494 | 491 | 490 | 489 | 486 | 487 | 482 |
| Percentage of AdditionalPaidInCapitalCommonStock | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 52.7 | 61.4 | 51.6 | 51.3 | 50.4 | 54.7 | 52.9 | 52.3 | 50.8 | 59.6 | 63.7 | 62.4 | 66.7 | 64.4 | 64.3 | 62.0 | 61.1 | 60.9 | 60.0 | 71.6 | 70.3 | 65.7 | 65.5 | 64.1 | 64.5 | 63.9 | 60.5 | 59.6 | 58.4 | 68.5 | 67.3 | 73.1 | 81.0 | 81.2 | 82.0 | 83.4 | 82.6 | 82.1 | 81.8 | 84.2 | 82.9 | 128.4 |
| 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 | 2010-12-31 |
| Value | -864.498 | -825.004 | -807.774 | -766.694 | -729.082 | -705.908 | -684.578 | -662.268 | -647.404 | -626.799 | -609.451 | -590.035 | -573.502 | -556.266 | -554.686 | -526.626 | -509.397 | -493.768 | -478.905 | -470.758 | -457.048 | -444.601 | -431.784 | -418.219 | -406.083 | -387.952 | -370.366 | -355.824 | -341.848 | -335.174 | -316.947 | -352.34 | -347.95 | -343.412 | -338.284 | -332.996 | -328.365 | -326.574 | -324.484 | -329.908 | -330.189 | -332.026 |
| 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 | -85.5 | -96.7 | -80.7 | -76.6 | -72.5 | -77.3 | -73.4 | -71.0 | -68.2 | -78.6 | -82.4 | -77.9 | -81.9 | -77.6 | -78.1 | -72.2 | -69.5 | -67.4 | -64.9 | -76.2 | -73.0 | -66.8 | -65.1 | -62.2 | -59.5 | -54.3 | -48.6 | -45.4 | -41.5 | -46.2 | -42.0 | -50.9 | -56.0 | -55.7 | -55.8 | -56.2 | -55.2 | -54.7 | -54.3 | -57.1 | -56.2 | -88.3 |
| Period End | 2021-06-30 | 2021-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 0 | 1000.0 | 0 | 0 | 1000.0 |
| Percentage of StockIssuedDuringPeriodValueNewIssues | 0.0 | 100.0 | 0.0 | 0.0 | 100.0 |
| Percentage of Assets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 0 | 1000.0 | 0 | 0 | 1000.0 |
| Percentage of StockIssuedDuringPeriodValueNewIssues | 0.0 | 100.0 | 0.0 | 0.0 | 100.0 |
| Percentage of Assets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Assets us-gaap:CommonStock | 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 | 8.476 | 7.831 | 6.431 | 7.147 | 6.666 | 5.559 | 5.415 | 5.311 | 5.714 | 3.771 | 4.83 | 5.292 | 5.149 | 4.161 |
| Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue | 100.0 | 100.0 | 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 | 0.0 | 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 |
| Value | 8.476 | 7.831 | 6.431 | 7.147 | 6.666 | 5.559 | 5.414 | 5.311 | 5.714 | 3.771 | 4.83 | 5.292 | 5.149 | 4.161 |
| Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue | 100.0 | 100.0 | 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 | 0.0 | 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 |
| Percentage of Assets us-gaap:AdditionalPaidInCapital | 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 |
| Value | 39 | 47 | 37 | 32 | 41 | 28 | 46 | 33 | 40 | 28 | 40 | 31 | 31 | 30 | 31 | 28 | 28 | 23 | 33 | 22 |
| 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 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 26.9 | 32.1 | 26.1 | 23.2 | 29.3 | 20.2 | 32.9 | 24.4 | 30.1 | 21.3 | 30.8 | 24.4 | 24.2 | 23.4 | 25.0 | 23.4 | 23.4 | 20.1 | 32.2 | 22.2 |
| 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 |
| Value | -17217000.0 | -15444000.0 | -15860000.0 | -13296000.0 | -13930000.0 | -12866000.0 | -9899000.0 | -12051000.0 | -11720000.0 | -13288000.0 | -10937000.0 | -12107000.0 | -11988000.0 | -14905000.0 | -10618000.0 | -10927000.0 | -12007000.0 | -12249000.0 | -7195000.0 | -8745000.0 |
| 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 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | -11.6 | -10.5 | -11.0 | -9.3 | -9.9 | -9.1 | -7.1 | -8.8 | -8.7 | -9.9 | -8.3 | -9.3 | -9.3 | -11.6 | -8.5 | -8.9 | -10.0 | -10.5 | -6.8 | -8.5 |
| 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 |
| Value | 112 | -163.667 | -45.768 | -44.977 | 13 | -38.572 | -34.124 | -32.817 | 120 | -31.809 | -37.51 | 40 | -29.127 | -26.791 | -24.982 | -24.998 | -24.516 | -22.771 | 100 | -20.925 |
| 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 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 76.3 | -111.5 | -31.8 | -31.6 | 9.4 | -27.4 | -24.3 | -24.0 | 89.6 | -23.7 | -28.4 | 31.4 | -22.5 | -20.8 | -19.9 | -20.3 | -20.5 | -19.4 | 95.8 | -20.3 |
| 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 |
| Value | 135 | -133.321 | -21.992 | -23.733 | 41 | -24.306 | 3.151 | -13.008 | 150 | -16.955 | -8.465 | 60 |
| 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 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 92.0 | -90.8 | -15.3 | -16.7 | 29.7 | -17.2 | 2.2 | -9.5 | 111.4 | -12.6 | -6.4 | 46.3 |
| 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 |
| Value | -0.939 | 4.497 | -1.818 | -2.153 | 1.814 | 2.439 | 2.873 | 4.454 | 2.259 | 2.572 | 3.59 | 2.712 | 2.192 | 2.623 | 14 | 3.209 | 3.397 | 3.229 | 0.771 | 2.82 | 3.31 | 2.323 | -11.539 | 2.355 | 0.653 | 0.822 | -5.074 | 1.139 | -0.457 | 1.229 |
| Percentage of DeferredIncomeTaxExpenseBenefit | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 22 | 21 | 22 | 21 | 19 | 19 | 20 | 20 | 19 | 20 | 20 | 20 | 20 | 19 | 19 | 19 | 18 | 18 | 20 | 18 | 18 | 17 | 18 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 16 | 16 | 15 | 15 | 16 | 15 | 15 | 15 | 15 | 15 | 14 | 14 | 14 | 14 | 14 |
| Percentage of DepreciationDepletionAndAmortization | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Value | 2330000.0 | -2420000.0 | 1600000.0 | 1009000.0 | -2697000.0 | 2790000.0 | -1110000.0 | 1048000.0 | 1259000.0 | -2264000.0 | 924000.0 | 1539000.0 | 2096000.0 | -1355000.0 | -156000.0 | 3976000.0 | 384000.0 | -43000.0 | 705000.0 | 1033000.0 | 1058000.0 | 387000.0 | -1000.0 | 8000.0 | 997000.0 | -2123000.0 | 1857000.0 | -889000.0 | 416000.0 | 2554000.0 | 1784000.0 | 1100000.0 | 234000.0 | 3175000.0 | -4210000.0 | 2040000.0 | 1349000.0 | -426000.0 |
| Percentage of IncreaseDecreaseInAccountsReceivable | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Value | 39 | 47 | 37 | 32 | 41 | 28 | 46 | 33 | 40 | 28 | 40 | 31 | 31 | 30 | 31 | 28 | 28 | 23 | 33 | 22 |
| 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 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 26.9 | 32.1 | 26.1 | 23.2 | 29.3 | 20.2 | 32.9 | 24.4 | 30.1 | 21.3 | 30.8 | 24.4 | 24.2 | 23.4 | 25.0 | 23.4 | 23.4 | 20.1 | 32.2 | 22.2 |
| 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 | 2011-06-30 | 2010-06-30 |
| Value | -2.493 | 18 | -6.62 | -4.955 | 8.564 | 9.227 | 7.466 | 13 | 7.136 | 9.217 | 7.1 | 8.231 | 6.552 | 6.784 | 2.115 | -0.883 |
| Percentage of ProfitLoss | 100.0 | 100.0 | 100.0 | 100.0 | 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 RevenueFromContractWithCustomerIncludingAssessedTax | -1.7 | 12.8 | -4.6 | -3.5 | 6.1 | 6.5 | 5.3 | 10.0 | 5.3 | 6.9 | 5.4 | 6.3 | 5.1 | 5.3 | 2.8 | -1.4 |
| 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 |
| Value | -17217000.0 | -15444000.0 | -15860000.0 | -13296000.0 | -13930000.0 | -12866000.0 | -9899000.0 | -12051000.0 | -11720000.0 | -13288000.0 | -10937000.0 | -12107000.0 | -11988000.0 | -14905000.0 | -10618000.0 | -10927000.0 | -12007000.0 | -12249000.0 | -7195000.0 | -8745000.0 |
| 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 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | -11.6 | -10.5 | -11.0 | -9.3 | -9.9 | -9.1 | -7.1 | -8.8 | -8.7 | -9.9 | -8.3 | -9.3 | -9.3 | -11.6 | -8.5 | -8.9 | -10.0 | -10.5 | -6.8 | -8.5 |
| 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 | 17 | 15 | 15 | 13 | 13 | 12 | 9.899 | 12 | 11 | 13 | 10 | 12 | 11 | 14 | 10 | 10 | 12 | 12 | 7.195 | 8.745 | 14 | 15 | 4.962 | 6.838 | 10 | 12 | 13 | 15 | 15 | 15 | 10 | 10 | 12 | 16 | 10 | 11 | 10 | 12 | 10 | 9.437 | 13 | 12 | 11 | 16 |
| Percentage of PaymentsToAcquirePropertyPlantAndEquipment | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Value | 112 | -163.667 | -45.768 | -44.977 | 13 | -38.572 | -34.124 | -32.817 | 120 | -31.809 | -37.51 | 40 | -29.127 | -26.791 | -24.982 | -24.998 | -24.516 | -22.771 | 100 | -20.925 |
| 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 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 76.3 | -111.5 | -31.8 | -31.6 | 9.4 | -27.4 | -24.3 | -24.0 | 89.6 | -23.7 | -28.4 | 31.4 | -22.5 | -20.8 | -19.9 | -20.3 | -20.5 | -19.4 | 95.8 | -20.3 |
| 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 |
| Value | 1.969 | 2.378 | 2.692 | 2.727 | 2.562 | 2.566 | 2.659 | 2.574 | 2.387 | 2.387 | 2.549 | 2.634 | 2.289 | 1.965 | 1.619 | 1.232 | 0.733 | 0.218 | 0.0 | 0.0 | 19 | 2.184 | 0.575 |
| Percentage of RepaymentsOfLongTermDebt | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-04 | 2020-12-31 | 2020-09-30 | 2020-05-05 | 2020-06-30 | 2020-03-27 | 2020-03-31 | 2019-12-09 | 2019-12-31 | 2019-09-09 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-01 | 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 | 2015-09-11 | 2015-09-30 | 2015-06-12 | 2015-06-30 | 2015-03-26 | 2015-03-31 | 2014-12-12 | 2014-12-31 | 2014-09-19 | 2014-09-30 | 2014-06-18 | 2014-06-30 | 2014-03-27 | 2014-03-31 | 2013-12-20 | 2013-09-25 | 2013-06-18 | 2013-03-15 | 2012-12-12 | 2012-09-12 |
| Value | 37 | 36 | 33 | 34 | 32 | 31 | 31 | 30 | 30 | 29 | 29 | 28 | 28 | 27 | 26 | 26 | 24 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 18 | 17 | 16 | 16 | 16 | 15 | 15 | 18 | 18 | 16 | 16 | 14 | 14 | 13 | 13 | 7.882 | 7.882 | 18 | 18 | 17 | 6.512 | 6.145 | 5.489 | 5.012 | 4.537 |
| Percentage of PaymentsOfDividends | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2021-09-03 | 2021-05-28 | 2020-09-04 |
| Value | 37 | 35 | 32 |
| Percentage of PaymentsOfDividends | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-26 | 2019-03-29 |
| Value | 34 | 26 |
| Percentage of PaymentsOfDividends | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 |
| Value | 4.225 | 0.0 | 2.826 | 0.0 | 12 | 19 | 8.119 | 10 | 15 | 17 | 14 | 0.0 | 0.0 | 1.3 | 0.035 |
| Percentage of PaymentsForRepurchaseOfCommonStock | 100.0 | 0.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 |
| Period End | 2021-05-31 |
| Value | 5.375 |
| Percentage of DebtInstrumentInterestRateStatedPercentage | 100.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations ccoi:SeniorSecuredNotesDue2022 | 0.0 |
| Period End | 2021-06-30 |
| Value | 3.5 |
| Percentage of DebtInstrumentInterestRateStatedPercentage | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations ccoi:SeniorSecuredNotesDue2026 | 0.0 |
| Period End | 2021-06-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 | 2019-06-25 |
| Value | 4.375 | 0.04375 | 0.04375 | 0.04375 | 0.04375 |
| Percentage of DebtInstrumentInterestRateStatedPercentage | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations ccoi:SeniorUnsecuredNotesOf4.375Due2024 | 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 | 54.09 | 46.21 | 41.01 | 36.37 | 32.35 | 28.37 | 25.41 | 19.36 | 14.87 | 13.17 |
| Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice | 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 | 9658000.0 | 9399000.0 |
| Percentage of DeferredTaxLiabilities | 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 |
| Value | 150 | 131 | 126 | 129 | 210 | 213 | 345 | 354 | 347 | 337 | 343 |
| Percentage of DeferredTaxAssetsValuationAllowance | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-04-06 |
| Value | 400000.0 |
| Percentage of AccruedInterestValue | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2016-03-31 |
| Value | 205 | 57 | -38.6 | 27 |
| Percentage of DebtInstrumentCovenantPermittedInvestmentsAndPayments | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 |
| Value | 0.2 | 0.7 | 0.3 | 0.5 |
| Percentage of FairMarketValueOfEquipmentReceivedInExchange | 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 |
| Value | -5.28 | 18 | -19.17 | -17.315 | -3.42 | 2.904 | -4.068 | 6.162 | 0.177 |
| Percentage of ForeignCurrencyTransactionGainLossUnrealizedOn2024EuroNotes | 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 | 2019-09-30 | 2019-06-30 |
| Value | 5.3 | -17.3 | -3.4 | 6.2 | 0.2 |
| Percentage of ForeignCurrencyTransactionGainLossUnrealizedOn2024EuroNotes | -100.4 | 99.9 | 99.4 | 100.6 | 113.0 |
| 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 |
| Value | 0.0 | 0.1 | 0.2 | 0.1 | 0.2 | 0.1 | 0.1 | 0.5 | 0.124 | 0.416 | 0.343 | 0.117 | 0.352 | 0.4 | 1.0 | 2.124 | 0.668 | 0.7 | 4.4 | 1.946 | 2.439 | 1.123 | 0.638 | 3.956 | 3.017 | 3.114 | 2.665 | 2.235 |
| Percentage of GainLossOnAssetExchangeTransactions | 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 | 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 | -615000.0 | 474000.0 | -245000.0 | -231000.0 | -303000.0 | -94000.0 | 599000.0 | 2053000.0 | -452000.0 | -3331000.0 | -28000.0 | 244000.0 |
| Percentage of IncreaseDecreaseInContractWithCustomerRefundLiability | 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 | 64000.0 | 744000.0 | 735000.0 | -699000.0 |
| Percentage of InterestAndOtherIncomeExpense | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 |
| Value | 505000.0 |
| Percentage of LossOnAmendmentOfFinanceLeases | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 |
| Value | 0 | 1000000.0 | 0 |
| Percentage of OperatingLeaseFixedAnnualRent | 0.0 | 100.0 | 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 |
| Value | 4.2 | 3.2 | 3.0 | 3.0 | 2.9 | 2.7 | 2.7 | 2.6 | 2.6 | 2.7 | 2.6 | 2.5 | 2.4 | 2.4 | 2.1 | 2.2 | 2.6 | 2.2 | 2.0 | 2.1 | 2.1 | 2.2 | 1.7 | 2.0 | 1.9 | 2.0 | 1.8 | 1.8 | 1.8 | 1.9 | 2.0 | 1.8 | 1.7 | 1.7 | 1.7 | 1.8 | 1.7 | 1.9 |
| Percentage of PropertyPlantAndEquipmentCompensationCostsCapitalized | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2021-04-06 |
| Value | 41.415 |
| Percentage of RedemptionPricePer1000AggregatePrincipalAmount | 100.0 |
| Period End | 2021-04-06 |
| Value | 41.415 |
| Percentage of RedemptionPricePer1000AggregatePrincipalAmount | 100.0 |
| Period End | 2021-04-06 |
| Value | 1900000.0 |
| Percentage of RedemptionValue | 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 | 100.0 | 0 | 0 | 0 | 100.0 | 0 | 0 |
| Percentage of SpeedPerSecondToBandwidthIntensiveUsers | 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 |
| Value | 0 | 100.0 | 0 | 0 | 0 | 100.0 | 0 | 0 |
| Percentage of SpeedPerSecondToBandwidthIntensiveUsers | 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 |
| Value | 1187000.0 | 2012000.0 | 1055000.0 | 1174000.0 | 1432000.0 | 1336000.0 |
| Percentage of AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease | 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 |
| Value | 400000.0 | 1200000.0 | 400000.0 | 400000.0 | 200000.0 | 200000.0 |
| Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries | 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 |
| Value | 971000.0 | 2476000.0 | 1338000.0 | 1085000.0 | 1293000.0 | 1131000.0 |
| Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs | 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 |
| Value | 453000.0 | 441000.0 | 468000.0 | 496000.0 | 453000.0 | 477000.0 | 479000.0 | 486000.0 | 428000.0 | 414000.0 | 407000.0 | 375000.0 | 381000.0 | 370000.0 | 340000.0 | 332000.0 | 287000.0 | 280000.0 | 226000.0 | 183000.0 | 480000.0 | 216000.0 | 181000.0 | 117000.0 | 37000.0 | -164000.0 | -293000.0 | -286000.0 | 1140000.0 | 1415000.0 | 1390000.0 | 1503000.0 | 1613000.0 | 1580000.0 | 1553000.0 |
| Percentage of AmortizationOfDebtDiscountPremium | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 9.882 | 6.336 | 10 | 19 | 39 | 3.164 | 2.965 | 2.78 | 4.932 | 3.63 | 4.976 | 4.339 | 7.119 | 3.616 | 4.49 | 6.525 | 5.623 | 5.957 | 5.319 | 6.237 | 3.602 | 3.281 | 7.974 | 10 | 3.466 | 4.217 | 9.6 | 11 | 3.447 | 4.224 | 5.779 | 6.425 | 2.382 | 18 | 7.852 | 4.218 | 3.423 | 2.312 | 5.857 | 7.535 | 11 | 16 | 3.355 | 4.823 |
| Percentage of CapitalLeaseObligationsIncurred | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Value | 4.6 | 4.6 | 4.2 | 4.2 | 4.2 | 4.3 | 4.3 | 4.4 |
| Percentage of CapitalizedContractCostAmortization | 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 | 2016-10-31 | 2016-12-31 | 2016-08-03 | 2016-09-30 | 2016-05-04 | 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 | 2013-12-20 | 2013-12-31 | 2013-09-30 | 2013-04-18 | 2013-06-30 | 2013-02-20 | 2013-03-31 | 2012-11-05 | 2012-12-31 | 2012-08-07 | 2012-08-31 | 2012-09-30 |
| Value | 0.78 | 0.755 | 0.735 | 0.705 | 0.68 | 0.66 | 0.64 | 0.62 | 0.6 | 0.58 | 0.56 | 0.54 | 0.52 | 0.5 | 0.48 | 0.46 | 0.44 | 0.42 | 0.4 | 0.4 | 0.38 | 0.38 | 0.37 | 0.37 | 0.36 | 0.35 | 0.34 | 0.42 | 0.35 | 0.31 | 0.3 | 0.17 | 0.39 | 0.37 | 0.37 | 0.14 | 0.13 | 0.13 | 0.12 | 0.12 | 0.11 | 0.11 | 0.1 | 0.1 | 0.1 |
| Percentage of CommonStockDividendsPerShareDeclared | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Value | 1800000.0 | 1800000.0 | 1600000.0 | 1800000.0 | 1600000.0 | 1700000.0 | 1700000.0 | 1700000.0 |
| Percentage of ContractWithCustomerLiabilityRevenueRecognized | 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 | 10000.0 | 69000.0 | 205000.0 | 36000.0 | 207000.0 | 87000.0 | 148000.0 | 536000.0 | 92000.0 | 416000.0 | 343000.0 | 117000.0 |
| Percentage of ContributionOfProperty | 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 |
| Value | 103.2 |
| Percentage of DebtInstrumentRedemptionPricePercentage | 100.0 |
| Period End | 2021-03-31 |
| Value | 103.2 |
| Percentage of DebtInstrumentRedemptionPricePercentage | 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 | 2015-12-11 | 2015-09-11 | 2015-06-12 | 2015-03-26 | 2014-12-12 | 2014-12-31 | 2014-09-19 | 2014-09-30 | 2014-06-18 | 2014-06-30 | 2014-03-27 | 2014-03-31 | 2013-12-20 | 2013-09-25 | 2013-06-18 | 2013-03-15 | 2012-12-12 | 2012-11-05 | 2012-09-12 | 2012-09-30 |
| Value | 37 | 36 | 34 | 32 | 31 | 30 | 29 | 28 | 27 | 26 | 26 | 24 | 23 | 22 | 16 | 15 | 18 | 16 | 14 | 14 | 13 | 13 | 7.882 | 7.882 | 18 | 18 | 17 | 6.512 | 6.1 | 5.5 | 5.0 | 5.0 | 4.5 | 4.5 |
| Percentage of DividendsCommonStockCash | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 37 | 36 | 34 | 32 | 31 | 30 | 29 | 28 | 27 | 26 | 26 | 24 | 23 | 22 |
| Percentage of DividendsCommonStockCash | 100.0 | 100.0 | 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 |
| Value | 658000.0 | -1316000.0 | 2065000.0 | 1560000.0 | 1214000.0 | -1326000.0 | 1077000.0 | -1583000.0 | 459000.0 | -495000.0 | -744000.0 | -245000.0 | -1900000.0 | 532000.0 | 486000.0 | 1415000.0 | 1774000.0 | 383000.0 | -1276000.0 | 21000.0 | -545000.0 | 1454000.0 | -978000.0 | -351000.0 | 574000.0 | -2935000.0 | -1488000.0 | -1836000.0 | 158000.0 | -387000.0 | 86000.0 | 945000.0 | -169000.0 | -735000.0 | 488000.0 | 571000.0 | -1065000.0 | 541000.0 | -911000.0 | -922000.0 | 236000.0 | 883000.0 | -13000.0 |
| Percentage of EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Value | 4.8 | 4.5 | 4.2 | 3.9 | 3.3 | 3.7 | 4.3 | 4.0 | 3.2 | 3.4 | 3.2 | 3.0 | 3.1 | 3.2 | 2.9 | 2.7 | 2.7 | 2.6 | 2.6 | 2.4 | 2.2 | 2.0 | 1.7 | 1.8 | 0.0 | 0.1 | 0.1 | 0.1 |
| Percentage of ExciseAndSalesTaxes | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Period End | 2021-05-06 |
| Value | 45 |
| Percentage of ExtinguishmentOfDebtAmount | 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 | 2015-12-31 |
| Value | 0.0 | 0.299 | 3.129 | 2.343 | 2.31 | 3.462 | 2.049 | 3.434 | 1.316 | 2.666 | 3.377 | 2.566 | 2.45 | 1.703 | 1.567 | 3.307 | -14.354 | -15.007 |
| Percentage of FairValueOfAssetsAcquired | 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 | 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 | 4.685 | 5.226 | 5.098 | 4.804 | 4.517 | 4.473 | 4.479 | 4.414 | 4.415 | 4.357 |
| Percentage of FinanceLeaseInterestExpense | 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 |
| Value | 5.111 | 4.993 | 4.879 | 4.636 | 4.708 | 4.441 | 8.663 | 1.663 | 3.485 | 3.295 |
| Percentage of FinanceLeaseInterestPaymentOnLiability | 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 | 6.192 | 5.744 | 4.598 | 9.509 | 3.716 | 6.167 | 2.062 | 2.029 | 1.976 | 3.03 | 2.128 | 2.099 | 3.755 | 2.304 |
| Percentage of FinanceLeasePrincipalPayments | 100.0 | 100.0 | 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 |
| Value | 6.378 | 6.346 | 6.733 | 6.382 | 4.973 | 4.762 | 4.972 | 4.963 | 4.917 | 4.971 |
| Percentage of FinanceLeaseRightOfUseAssetAmortization | 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 |
| Value | -14000.0 | 0 | 2547000.0 |
| Percentage of ForeignCurrencyTransactionGainLossRealized | 100.0 | 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 | 2019-09-30 |
| Value | -5.28 | 18 | -19.2 | -17.3 | -3.4 | 2.9 | -4.0 | 6.1 |
| Percentage of ForeignCurrencyTransactionGainLossUnrealized | 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 |
| Value | 0.129 | -0.371 | 0.626 | -0.982 | 0.448 | 0.454 | 0.227 | -0.353 | 0.253 | 0.231 | 0.382 | 0.288 | -0.045 | 0.484 | 0.439 | 0.766 | 1.456 | 2.172 | 0.55 | 0.644 | 4.294 | 2.186 | 1.848 | 1.181 | 0.815 | 1.022 | 2.602 | 2.821 | 2.701 | 2.258 | 0.977 | 0.147 | 0.012 | -0.135 | 0.773 | 0.166 | -0.154 | 0.186 |
| Percentage of GainLossOnDispositionOfAssets | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Value | 3.9 |
| Percentage of GainLossOnRepurchaseOfDebtInstrument | 100.0 |
| Period End | 2021-03-31 |
| Value | 3.9 |
| Percentage of GainLossOnRepurchaseOfDebtInstrument | 100.0 |
| Period End | 2021-12-01 |
| Value | 10 |
| Percentage of GainLossOnRepurchaseOfDebtInstrument | 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 |
| Value | 0.0 | 0.018 | 0.009 | 0.099 | 0.205 | 0.039 | 0.251 | 0.087 | 0.185 | 0.536 | 0.092 | 0.416 | 0.357 | 0.117 | 0.319 | 0.397 | 1.023 | 2.124 | 2.023 | 0.687 | 4.439 | 1.946 | 2.023 | 1.152 | 0.719 | 1.548 | 2.81 | 3.114 | 2.731 | 2.295 |
| Percentage of GainLossOnSaleOfPropertyPlantEquipment | 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 |
| 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 |
| Value | 0.853 | 2.951 | -0.501 | -4.306 | 0.456 | 1.067 | 3.692 | -3.738 | 7.866 | -2.778 | 5.377 | -3.055 | -0.413 | -2.005 | -1.16 | 0.673 | -0.424 | -1.66 | 5.769 | -4.266 | 0.386 | 8.379 | -3.41 | 0.077 | -1.399 | 2.088 | -0.119 | -3.206 | 9.288 | -1.466 | 10 | -8.125 | 3.333 | 0.314 | 6.604 | -3.477 | 2.453 | -1.209 |
| Percentage of IncreaseDecreaseInOperatingLiabilities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Value | 130000.0 | -2826000.0 | -482000.0 | 788000.0 | -628000.0 | 3093000.0 | -1132000.0 | 1315000.0 | 360000.0 | 3187000.0 | -225000.0 | 32000.0 | -582000.0 | 1213000.0 | -501000.0 | -1845000.0 | 133000.0 | 1067000.0 | -333000.0 | -179000.0 | 1218000.0 | 2217000.0 | -356000.0 | 130000.0 | -1426000.0 | 4550000.0 | -552000.0 | -788000.0 | -1465000.0 | 5143000.0 | 875000.0 | -1926000.0 | 1969000.0 | 2724000.0 | -532000.0 | -838000.0 | -377000.0 | 1288000.0 |
| Percentage of IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 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 | 0.548 | 0.484 | 0.735 | 2.205 | -2.057 | 8.347 | 1.753 | 1.827 | 2.063 | 1.937 | 0.189 | 1.694 | 0.165 | 1.632 | 1.015 | 0.854 | 0.344 | 0.207 | 0.335 | 0.133 | 0.39 | 0.05 | 0.417 | 0.097 | -0.008 | 0.14 | 0.268 | 0.137 | 1.093 | 0.292 | 0.589 | 0.658 | 0.925 | 0.397 | 0.148 | 0.375 | 0.238 | 0.081 | 0.298 |
| Percentage of InterestAndOtherIncome | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Value | 15 | 15 | 16 | 15 | 13 | 12 | 16 | 11 | 12 | 12 |
| Percentage of LeaseCost | 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 |
| Value | 4.671 | 4.417 | 4.502 | 4.269 | 4.405 | 4.187 | 7.245 | 1.662 | 3.486 | 3.295 |
| Percentage of OperatingLeaseCost | 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 |
| Value | 4.715 | 5.396 | 4.971 | 5.165 | 4.205 | 4.78 | 5.002 | 4.13 | 4.333 | 4.494 |
| Percentage of OperatingLeasePayments | 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 |
| Value | 1.776 | -5.21 | 6.192 | 5.408 | 2.913 | -3.493 | 3.35 | -4.709 | 1.786 | -1.825 | -2.256 | -0.485 | -6.198 | 2.611 | 1.312 | 3.79 | 6.163 | 1.328 | -5.295 | 0.688 | -1.967 | 4.074 | -2.746 | 0.228 | 1.683 | -7.396 | -3.058 | -5.034 | -0.044 | -0.462 | 0.595 | 2.341 | 0.326 | -1.793 | 1.193 | 1.501 | -3.068 | 1.623 |
| Percentage of OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 1.776 | -5.21 | 6.192 | 5.408 | 2.913 | -3.493 | 3.35 | -4.709 | 1.786 | -1.825 | -2.256 | -0.485 | -6.198 | 2.611 |
| Percentage of OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent | 100.0 | 100.0 | 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 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 0.0 | 0.0 | 0.006 | 0.0 | 152 |
| Percentage of ProceedsFromIssuanceOfUnsecuredDebt | 0.0 | 0.0 | 100.0 | 0.0 | 100.0 |
| Period End | 2021-03-31 | 2020-12-31 |
| Value | -119680000.0 | 0 |
| Percentage of ProceedsFromRepaymentsOfNotesPayable | 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 | 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 | 660000.0 | 215000.0 | 207000.0 | 186000.0 | 271000.0 | 718000.0 | 367000.0 | 351000.0 | 746000.0 | 173000.0 | 248000.0 | 518000.0 | 705000.0 | 297000.0 | 303000.0 | 433000.0 | 186000.0 | 300000.0 | 326000.0 | 264000.0 | 424000.0 | 206000.0 | 135000.0 | 69000.0 | 89000.0 | 130000.0 | 95000.0 | 137000.0 | 146000.0 | 155000.0 | 244000.0 | 237000.0 | 522000.0 | 215000.0 | 74000.0 | 172000.0 | 64000.0 | 94000.0 | 262000.0 | 216000.0 | 88000.0 | 67000.0 | 145000.0 | 52000.0 |
| Percentage of ProceedsFromStockOptionsExercised | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Value | 800000.0 | 800000.0 | 800000.0 | 1300000.0 | 1100000.0 |
| Percentage of ProvisionForDoubtfulAccounts | 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 |
| Value | 500000.0 | 400000.0 | 400000.0 | 500000.0 | 500000.0 | 400000.0 | 500000.0 | 300000.0 | 500000.0 | 300000.0 | 400000.0 | 500000.0 | 500000.0 |
| Percentage of RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty | 100.0 | 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 | 2021-05-31 |
| Value | 45 |
| Percentage of RepaymentsOfSeniorDebt | 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 |
| Value | 9.882 | 6.336 | 10 | 19 | 39 | 3.164 | 2.965 | 2.78 | 4.932 | 3.63 |
| Percentage of RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability | 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 |
| Value | 9.811 | 2.72 | 10 | 4.172 | 15 | 5.53 | 2.842 | 5.455 | 1.141 | 0.316 |
| Percentage of RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability | 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 | 2020-06-30 | 2020-03-31 |
| Value | 323700 | 0.13528 | 0.31975 |
| Percentage of StockIssuedDuringPeriodSharesShareBasedCompensation | 100.0 | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-06-30 | 2020-03-31 |
| Value | 19 | 10 | 23 |
| Percentage of StockIssuedDuringPeriodValueShareBasedCompensation | 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 | 660000.0 | 215000.0 | 208000.0 | 185000.0 | 270000.0 | 719000.0 | 367000.0 | 351000.0 | 745000.0 | 173000.0 | 248000.0 | 518000.0 | 704000.0 | 297000.0 |
| Percentage of StockIssuedDuringPeriodValueStockOptionsExercised | 100.0 | 100.0 | 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 | 660000.0 | 215000.0 | 208000.0 | 185000.0 | 270000.0 | 719000.0 | 368000.0 | 351000.0 | 745000.0 | 173000.0 | 248000.0 | 518000.0 | 704000.0 | 297000.0 |
| Percentage of StockIssuedDuringPeriodValueStockOptionsExercised | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.3 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 4.226 | 0.269 |
| Percentage of StockRepurchasedAndRetiredDuringPeriodValue | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 4.226 | 0.269 |
| Percentage of StockRepurchasedAndRetiredDuringPeriodValue | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-10-01 | 2020-09-30 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2016-12-31 | 2016-09-30 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 |
| Value | 4.2 | 3.1 | 0.3 | 0.0 | 0.0 | 1.8 | -1.6999955 | 1.7 | 0.0 | 12 | 19 | 8.119 | 10 | 15 | 17 | 14 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 1.3 | 0.0 |
| Percentage of StockRepurchasedDuringPeriodValue | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 |
| Period End | 2021-04-06 |
| Value | 9.7049 |
| Percentage of AccruedInterestPer1000AggregatePrincipalAmount | 100.0 |
| Period End | 2021-04-06 |
| Value | 9.7049 |
| Percentage of AccruedInterestPer1000AggregatePrincipalAmount | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 40 | 32 |
| Percentage of DeferredTaxAssetsOperatingLeases | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 37 | 29 |
| Percentage of DeferredTaxLiabilitiesRightOfUseAssets | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 29 | 25 | 21 | 20 |
| Percentage of FinanceLeaseLiabilityPaymentsDueAdditional | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 |
| Value | 1.0 |
| Percentage of FixedChargeCoverageRatio | 100.0 |
| Period End | 2021-06-30 |
| Value | 2.0 |
| Percentage of FixedChargeCoverageRatio | 200.0 |
| Period End | 2021-06-30 |
| Value | 1.0 |
| Percentage of FixedChargeCoverageRatio | 100.0 |
| Period End | 2021-06-30 |
| Value | 1.0 |
| Percentage of FixedChargeCoverageRatio | 100.0 |
| Period End | 2021-06-30 |
| Value | 2.0 |
| Percentage of FixedChargeCoverageRatio | 200.0 |
| Period End | 2021-06-30 |
| Value | 2.0 |
| Percentage of FixedChargeCoverageRatio | 200.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 |
| Value | 105 | 97 | 99 | 90 | 87 | 75 | 73 |
| Percentage of LeaseRightOfUseAsset | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 870 | 744 |
| Percentage of OperatingLossCarryforwardsNotSubjectToExpiration | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 1000 | 896 |
| Percentage of OperatingLossCarryforwardsNotSubjectToExpiration | 114.9 | 120.4 |
| Period End | 2021-06-30 |
| Value | 1.0 |
| Percentage of RatioOfAdditionalIndebtednessToNetCapital | 100.0 |
| Period End | 2021-06-30 |
| Value | 1.0 |
| Percentage of RatioOfAdditionalIndebtednessToNetCapital | 100.0 |
| Period End | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 |
| Value | 3.5 | 4.25 | 4.25 | 4.25 | 3.5 | 3.5 | 3.5 |
| Percentage of RatioOfAdditionalIndebtednessToNetCapital | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 |
| Value | 4.0 |
| Percentage of RatioOfAdditionalIndebtednessToNetCapital | 400.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | 4.25 | 4.0 | 4.0 | 4.0 | 3.5 | 4.0 |
| Percentage of RatioOfAdditionalIndebtednessToNetCapital | 425.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-31 | 2020-12-31 | 2020-09-30 | 2020-06-30 |
| Value | 4.25 | 3.5 | 3.5 | 4.0 |
| Percentage of RatioOfAdditionalIndebtednessToNetCapital | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-04-06 |
| Value | 45 |
| Percentage of RedemptionForDebtNoticeIssued | 100.0 |
| Period End | 2021-04-06 |
| Value | 45 |
| Percentage of RedemptionForDebtNoticeIssued | 100.0 |
| Period End | 2021-03-31 |
| Value | 733000.0 |
| Percentage of UnamortizedDebtIssuanceExpenseCurrent | 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 |
| Value | 5918000.0 | 6053000.0 | 4212000.0 | 2360000.0 | 4037000.0 | 3347000.0 | 1359000.0 | 1128000.0 | 692000.0 | 1210000.0 | 1448000.0 |
| Percentage of AccrualForTaxesOtherThanIncomeTaxesCurrent | 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 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 |
| Value | -4740000.0 | -6516000.0 | -1306000.0 | -7498000.0 | -12906000.0 | -15819000.0 | -12326000.0 | -15676000.0 | -10967000.0 | -12753000.0 | -10928000.0 | -8672000.0 | -8187000.0 | -1989000.0 | -4600000.0 | -5912000.0 | -9702000.0 | -15865000.0 | -17193000.0 | -11898000.0 | -12586000.0 | -10619000.0 | -14693000.0 | -11947000.0 | -12175000.0 | -13858000.0 | -6462000.0 | -3404000.0 | 1630000.0 | 2136000.0 | 1541000.0 | -800000.0 | -1126000.0 | 667000.0 |
| 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 | 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 | 1673000.0 | 1457000.0 | 1921000.0 | 2204000.0 | 2115000.0 | 1976000.0 | 1771000.0 | 1758000.0 | 1782000.0 | 1353000.0 | 1263000.0 | 1614000.0 | 1131000.0 | 1110000.0 | 1499000.0 | 2044000.0 | 1731000.0 | 1543000.0 | 1734000.0 | 1804000.0 | 1102000.0 | 1241000.0 | 1757000.0 | 1589000.0 | 1872000.0 | 1902000.0 | 1707000.0 | 2012000.0 | 1817000.0 | 2192000.0 | 1871000.0 | 1905000.0 | 1879000.0 | 1759000.0 | 3083000.0 | 2822000.0 | 2914000.0 | 3027000.0 | 3345000.0 | 2593000.0 | 2602000.0 | 2464000.0 |
| 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 | 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 | 39 |
| Percentage of CapitalLeasesFutureMinimumPaymentsDue | 100.0 |
| Period End | 2020-12-31 |
| Value | 19 |
| Percentage of CapitalLeasesFutureMinimumPaymentsDueCurrent | 100.0 |
| Period End | 2020-12-31 |
| Value | 1240000.0 |
| Percentage of CapitalLeasesFutureMinimumPaymentsDueInFiveYears | 100.0 |
| Period End | 2020-12-31 |
| Value | 3119000.0 |
| Percentage of CapitalLeasesFutureMinimumPaymentsDueInFourYears | 100.0 |
| Period End | 2020-12-31 |
| Value | 5586000.0 |
| Percentage of CapitalLeasesFutureMinimumPaymentsDueInThreeYears | 100.0 |
| Period End | 2020-12-31 |
| Value | 8531000.0 |
| Percentage of CapitalLeasesFutureMinimumPaymentsDueInTwoYears | 100.0 |
| Period End | 2020-12-31 |
| Value | 1690000.0 |
| Percentage of CapitalLeasesFutureMinimumPaymentsDueThereafter | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 |
| Value | 20 | 18 | 18 |
| Percentage of CapitalizedContractCostNet | 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 | 2016-12-31 |
| Value | 3.4 | 5.3 | 7.7 | 10 | 12 | 12 | 12 | 12 | 11 | 12 | 11 | 12 | 12 | 11 | 10 | 5.5 |
| Percentage of ContractualObligation | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2021-05-06 |
| Value | 284 |
| Percentage of DebtInstrumentCarryingAmount | 100.0 |
| Period End | 2021-06-30 |
| Value | 500 |
| Percentage of DebtInstrumentCarryingAmount | 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 | 2019-06-25 |
| Value | 350 | 350 | 350 | 350 | 350 | 135 | 135 | 135 | 135 |
| Percentage of DebtInstrumentCarryingAmount | 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 | 2018-07-31 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 |
| Value | 329 | 445 | 445 | 445 | 189 | 445 | 445 | 445 | 445 | 445 | 375 | 375 | 375 | 375 | 375 |
| Percentage of DebtInstrumentCarryingAmount | 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 | 2020-12-31 | 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 |
| Value | 445 | 445 | 189 | 445 | 189 | 189 | 189 | 189 | 189 | 189 | 189 | 189 | 189 |
| Percentage of DebtInstrumentCarryingAmount | 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 | 2021-05-06 |
| Value | 284 |
| Percentage of DebtInstrumentCarryingAmount | 100.0 |
| Period End | 2020-09-30 |
| Value | 410 |
| Percentage of DebtInstrumentFaceAmount | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 |
| Value | 284 | 115 |
| Percentage of DebtInstrumentFaceAmount | 0.0 | 0.0 |
| Period End | 2021-06-30 | 2020-09-30 | 2020-06-30 | 2020-06-03 | 2019-06-30 | 2019-06-25 |
| Value | 350 | 350 | 215 | 215 | 135 | 135 |
| Percentage of DebtInstrumentFaceAmount | 0.0 | 85.3 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-31 | 2020-09-30 | 2020-06-30 | 2019-06-30 | 2018-08-31 | 2016-12-31 | 2015-02-28 |
| Value | 115 | 445 | 350 | 135 | 70 | 125 | 250 |
| Percentage of DebtInstrumentFaceAmount | 0.0 | 108.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 |
| Value | 510 |
| Percentage of DebtInstrumentFairValue | 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 | 424 | 419 | 437 | 416 | 393 | 151 | 155 | 149 |
| Percentage of DebtInstrumentFairValue | 83.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-31 | 2020-09-30 | 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 | 2015-09-30 | 2015-06-30 |
| Value | 337 | 455 | 447 | 191 | 461 | 461 | 457 | 438 | 449 | 383 | 383 | 392 | 396 | 245 | 247 |
| Percentage of DebtInstrumentFairValue | 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 | 2020-12-31 | 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 | 2015-09-30 | 2015-06-30 |
| Value | 458 | 456 | 187 | 466 | 191 | 191 | 191 | 188 | 190 | 190 | 191 | 193 | 194 | 191 | 190 |
| Percentage of DebtInstrumentFairValue | 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 | 2017-12-31 | 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 | 0.041 | 0.08 | 0.136 | 0.245 | 0.291 | 0.313 | 0.35 | 0.391 | 0.396 | 0.436 | 0.395 | 0.337 | 1.414 | 3.099 | 4.75 | 6.365 | 7.947 | 9.494 | 11 | 12 | 13 | 15 | 16 | 18 | 20 |
| Percentage of DebtInstrumentUnamortizedDiscount | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2016-12-31 |
| Value | 0.041 | 0.1 | 0.1 | 0.3 | 0.3 | 0.3 | 0.4 | 0.4 | 0.4 | 0.5 | 0.4 | 0.5 | 0.5 | 0.4 | 0.4 | 0.3 |
| Percentage of DebtInstrumentUnamortizedDiscount | 100.0 | 125.0 | 73.5 | 122.4 | 103.1 | 95.8 | 114.3 | 102.3 | 101.0 | 114.7 | 101.3 | 0.0 | 0.0 | 0.0 | 118.7 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 1142000.0 | 1164000.0 | 1183000.0 | 0 |
| Percentage of DebtInstrumentUnamortizedPremium | 100.0 | 100.0 | 100.0 | 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 | 2016-12-31 |
| Value | 544000.0 | 656000.0 | 767000.0 | 877000.0 | 985000.0 | 1092000.0 | 1197000.0 | 1302000.0 | 1405000.0 | 1507000.0 | 340000.0 | 360000.0 | 382000.0 | 402000.0 | 462000.0 |
| Percentage of DebtInstrumentUnamortizedPremium | 47.6 | 56.4 | 64.8 | 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 |
| Value | 430000.0 |
| Percentage of DebtInstrumentUnamortizedPremiumCurrent | 100.0 |
| Period End | 2021-06-30 |
| Value | 1698000.0 |
| Percentage of DebtInstrumentUnamortizedPremiumNoncurrent | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 |
| Value | 959000.0 | 1020000.0 | 1142000.0 |
| Percentage of DebtInstrumentUnamortizedPremiumNoncurrent | 56.5 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 180 | 172 | 131 | 129 | 125 | 115 | 1.398 | 4.015 | 5.62 |
| Percentage of DeferredIncomeTaxLiabilities | 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 | 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 |
| Value | 4651000.0 | 4316000.0 | 4504000.0 | 4280000.0 | 4374000.0 | 4475000.0 | 4758000.0 | 4334000.0 | 4303000.0 | 4307000.0 | 4174000.0 | 4132000.0 | 3978000.0 | 3893000.0 |
| 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 |
| 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 | 320 | 293 | 261 | 276 | 378 | 374 | 398 | 412 | 358 | 352 |
| 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 | 2010-12-31 |
| Value | 273 | 255 | 255 | 271 | 373 | 370 | 366 | 402 | 345 | 335 | 340 |
| Percentage of DeferredTaxAssetsOperatingLossCarryforwards | 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 | 2010-12-31 |
| Value | 1965000.0 | 2261000.0 | 2458000.0 | 2771000.0 | 2237000.0 | 2317000.0 | 2208000.0 | 2775000.0 | 2758000.0 | 2437000.0 | 2748000.0 |
| Percentage of DeferredTaxAssetsTaxCreditCarryforwards | 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 | 2011-12-31 | 2010-12-31 |
| Value | 4901000.0 | 4116000.0 | 3322000.0 | 2327000.0 | 2279000.0 | 1474000.0 | 849000.0 | 566000.0 | 705000.0 |
| Percentage of DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost | 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 |
| Value | 105 | 107 | 101 | 106 | 95 | 97 |
| Percentage of DeferredTaxLiabilitiesDeferredExpenseReservesAndAccruals | 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 | 2011-12-31 | 2010-12-31 |
| Value | 37 | 34 | 29 | 22 | 29 | 18 | -7.857 | -6.685 |
| Percentage of DeferredTaxLiabilitiesPropertyPlantAndEquipment | 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 | 2017-12-31 |
| Value | 15 | 13 | 14 | 13 | 13 | 13 | 13 | 13 | 14 | 14 | 11 | 5.572 |
| Percentage of DepositsAssetsNoncurrent | 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 | 2010-12-31 |
| Value | 8024000.0 | 6613000.0 | 7695000.0 | 5139000.0 | 4170000.0 | 3455000.0 | 3371000.0 | 2952000.0 | 2358000.0 | 2160000.0 | 2155000.0 |
| Percentage of EmployeeRelatedLiabilitiesCurrent | 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 | 40 |
| Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 224 | 218 | 219 | 212 |
| Percentage of FinanceLeaseLiability | 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 |
| Value | 16 | 15 | 15 | 15 | 14 | 8.268 | 8.154 | 7.884 | 7.7 | 7.293 | 7.074 |
| Percentage of FinanceLeaseLiabilityCurrent | 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 |
| Value | 208 | 202 | 203 | 197 | 189 | 159 | 161 | 160 | 160 | 157 | 156 |
| Percentage of FinanceLeaseLiabilityNoncurrent | 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 |
| Value | 394 | 387 | 392 | 383 |
| Percentage of FinanceLeaseLiabilityPaymentsDue | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 34 | 34 | 34 | 33 |
| Percentage of FinanceLeaseLiabilityPaymentsDueInNextRollingTwelveMonths | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 235 | 229 | 232 | 225 |
| Percentage of FinanceLeaseLiabilityPaymentsDueInRollingAfterYearFive | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 25 | 25 | 27 | 28 |
| Percentage of FinanceLeaseLiabilityPaymentsDueInRollingYearFive | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 32 | 32 | 32 | 31 |
| Percentage of FinanceLeaseLiabilityPaymentsDueInRollingYearFour | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 32 | 32 | 32 | 31 |
| Percentage of FinanceLeaseLiabilityPaymentsDueInRollingYearThree | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 33 | 33 | 33 | 32 |
| Percentage of FinanceLeaseLiabilityPaymentsDueInRollingYearTwo | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 169 | 169 | 172 | 170 |
| Percentage of FinanceLeaseLiabilityUndiscountedExcessAmount | 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 |
| Value | 9.8 | 10.1 | 10.3 | 10.5 | 0.108 | 0.109 | 11.0 | 10.5 | 0.106 | 0.107 |
| Percentage of FinanceLeaseWeightedAverageDiscountRatePercent | 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 |
| Value | 8.268 | 10 | 11 | 10 | 10 | 7.781 | 11 | 11 | 11 | 7.392 | 3.543 |
| Percentage of InterestPayableCurrent | 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 |
| Value | 0.4 |
| Percentage of InterestPayableCurrent | 0.0 |
| Period End | 2021-03-31 |
| Value | 0.4 |
| Percentage of InterestPayableCurrent | 0.0 |
| Period End | 2021-12-01 |
| Value | 11 |
| Percentage of InterestPayableCurrent | 0.0 |
| Period End | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 114 | 118 | 103 |
| Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive | 100.0 | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 12 | 12 | 12 |
| Percentage of LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFive | 100.0 | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 14 | 15 | 14 |
| Percentage of LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFour | 100.0 | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 16 | 16 | 15 |
| Percentage of LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree | 100.0 | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 16 | 16 | 16 |
| Percentage of LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearTwo | 100.0 | 100.0 | 100.0 |
| Period End | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 17 | 17 | 17 |
| Percentage of LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 429 | 151 |
| Percentage of LongTermDebtFairValue | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 6922000.0 |
| Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths | 100.0 |
| Period End | 2020-12-31 |
| Value | 429 |
| Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour | 100.0 |
| Period End | 2020-12-31 |
| Value | 445 |
| Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 3500000.0 | 3400000.0 | 3300000.0 | 3300000.0 |
| Percentage of LossContingencyRangeOfPossibleLossPortionNotAccrued | 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 |
| Value | 5.5 | 5.6 | 5.6 | 5.4 | 0.054 | 0.056 | 5.6 | 5.7 | 0.057 | 0.056 |
| Percentage of OperatingLeaseWeightedAverageDiscountRatePercent | 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 | 1100 | 994 | 1000 | 1000 | 1200 | 1200 | 1200 | 1300 | 1100 | 1100 |
| Percentage of OperatingLossCarryforwards | 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 | 5.3 | 3.3 | 4.0 | 5.3 | 1.1 | 1.7 | 1.8 | 1.8 |
| Percentage of OperatingLossCarryforwards | 0.5 | 0.3 | 0.4 | 0.5 | 0.1 | 0.1 | 0.1 | 0.1 |
| 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 | 60 | 97 | 131 | 150 | 465 | 446 | 390 | 395 |
| Percentage of OperatingLossCarryforwards | 5.5 | 9.8 | 13.1 | 15.1 | 38.8 | 37.2 | 32.5 | 30.4 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 1000 | 890 |
| Percentage of OperatingLossCarryforwards | 90.9 | 89.5 |
| Period End | 2020-12-31 | 2019-12-31 | 2019-03-31 | 2018-12-31 | 2018-03-31 | 2017-12-31 |
| Value | 1.1 | 3.3 | 1.7 | 3.2 | 0.4 | 9.1 |
| Percentage of PropertyPlantAndEquipmentFairValueDisclosure | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 |
| Value | 1.0 |
| Percentage of RatioOfIndebtednessToNetCapital1 | 100.0 |
| Period End | 2021-06-30 |
| Value | 1.0 |
| Percentage of RatioOfIndebtednessToNetCapital1 | 100.0 |
| Period End | 2021-06-30 |
| Value | 1.0 |
| Percentage of RatioOfIndebtednessToNetCapital1 | 100.0 |
| Period End | 2021-06-30 |
| Value | 6.0 |
| Percentage of RatioOfIndebtednessToNetCapital1 | 600.0 |
| Period End | 2021-06-30 |
| Value | 6.0 |
| Percentage of RatioOfIndebtednessToNetCapital1 | 600.0 |
| Period End | 2021-03-31 |
| Value | 328 |
| Percentage of SecuredDebtCurrent | 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 | 55.7 | 45.4 | 41.12 | 38.11 | 35.94 | 32.25 | 28.26 | 18.69 | 16.12 | 11.34 |
| Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue | 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 | 47.63 |
| Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice | 100.0 |
| Period End | 2020-12-31 |
| Value | 1700000.0 |
| Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue | 100.0 |
| Period End | 2020-12-31 |
| Value | 1600000.0 |
| Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue | 100.0 |
| Period End | 2020-12-31 |
| Value | 52.71 |
| Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice | 100.0 |
| Period End | 2020-12-31 |
| Value | 1500000.0 |
| Percentage of SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1 | 100.0 |
| Period End | 2020-12-31 |
| Value | 50 |
| Percentage of StockRepurchaseProgramAuthorizedAmount1 | 100.0 |
| Period End | 2021-06-30 | 2021-03-31 | 2020-12-31 | 2020-09-30 |
| Value | 30 | 30 | 30 | 34 |
| Percentage of StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-06-30 |
| Value | 1277000.0 |
| Percentage of UnamortizedDebtIssuanceExpense | 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 | 2538000.0 | 2751000.0 | 2961000.0 | 3166000.0 | 1480000.0 | 1341000.0 | 1410000.0 | 1483000.0 |
| Percentage of UnamortizedDebtIssuanceExpense | 198.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-06-30 | 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 |
| Value | 1052000.0 | 1052000.0 | 1267000.0 | 3365000.0 | 1690000.0 | 1897000.0 | 2101000.0 | 2301000.0 | 2500000.0 | 2695000.0 | 2887000.0 | 1668000.0 | 1769000.0 | 1870000.0 | 1969000.0 | 2257000.0 |
| Percentage of UnamortizedDebtIssuanceExpense | 82.4 | 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 |
| 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 | 2016-12-31 |
| Value | 857000.0 | 857000.0 | 696000.0 | 857000.0 | 1015000.0 | 1171000.0 | 1325000.0 | 1476000.0 | 1625000.0 | 1772000.0 | 1917000.0 | 2060000.0 | 2200000.0 | 2575000.0 |
| Percentage of UnamortizedDebtIssuanceExpense | 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 | 2020-12-31 |
| Value | 700000.0 |
| Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnFifthAnniversary | 100.0 |
| Period End | 2020-12-31 |
| Value | 2500000.0 |
| Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnFirstAnniversary | 100.0 |
| Period End | 2020-12-31 |
| Value | 700000.0 |
| Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary | 100.0 |
| Period End | 2020-12-31 |
| Value | 800000.0 |
| Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnSecondAnniversary | 100.0 |
| Period End | 2020-12-31 |
| Value | 700000.0 |
| Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnThirdAnniversary | 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 | 2017-12-31 |
| Value | 3.324 | 5.035 | 6.786 | 8.292 | 9.374 | 9.122 | 9.063 | 9.078 | 8.693 | 8.686 | 8.283 | 14 |
| Percentage of UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount | 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 |
| Value | 10 | 7.6 | 8.5 | 5.0 | 5.6 | 8.1 | 6.6 | 24 | 40 |
| Percentage of UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount | 156.2 | 83.9 | 102.6 | 33.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 |
| Value | 21 | 20 | 12 |
| Percentage of UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount | 309.5 | 224.0 | 152.1 |
| Period End | 2020-12-31 |
| Value | 15 |
| Percentage of UnrecordedUnconditionalPurchaseObligationDueAfterFiveYears | 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 | 150 | 131 | 126 | 129 | 210 | 213 | 345 | 354 | 347 | 337 | 343 | 340 |
| Percentage of ValuationAllowancesAndReservesBalance | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
