| 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:CommonStockValue | ▄▄▄▄▄▄▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁███ | 0.003 | 0.003 | 0.003 | 0.003 | 0.003 | 0.003 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.004 | 0.004 | 0.004 |
| us-gaap:EarningsPerShareBasic | ▇█▁▅▆▆▅▄▅▅▅▅▅▅▆▅▅▅▅▅▅▅▅▅▅ | 1.86 | 3.23 | -3.83 | 0.64 | 1.29 | 0.84 | 0.31 | -0.34 | 0.11 | 0.67 | 0.17 | -0.23 | 0.01 | 0.15 | 0.73 | 0.65 | 0.47 | -0.01 | 0.02 | -0.06 | 0.09 | 0.53 | 0.08 | -0.02 | 0.02 |
| us-gaap:EarningsPerShareDiluted | ▇█▁▅▆▆▅▅▅▆▅▅▅▅▆▆▅▅▅▅▅▅▅▅▅ | 1.75 | 3.07 | -3.83 | 0.59 | 1.21 | 0.82 | 0.3 | -0.34 | 0.1 | 0.64 | 0.17 | -0.23 | 0.01 | 0.15 | 0.71 | 0.64 | 0.47 | -0.01 | 0.01 | -0.06 | 0.09 | 0.53 | 0.08 | -0.02 | 0.02 |
| us-gaap:IncomeLossFromContinuingOperationsPerBasicShare | ▄ | 1.8600000000000002e-06 | NA | NA | NA | 1.29e-06 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| COGS Ratio us-gaap:StatementBusinessSegments rily:AuctionAndLiquidationSegment | █▁ | 44.185 | 8.251 | NA | -44.395 | 11.286 | 34.916 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| COGS Ratio us-gaap:StatementBusinessSegments rily:PrincipalInvestmentsUnitedOnlineAndMagicJackSegment | █▁ | 21.602 | 21.431 | NA | 23.686 | 23.863 | 25.778 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| Operating Margin us-gaap:StatementBusinessSegments rily:AuctionAndLiquidationSegment | ▄ | 44.185 | NA | NA | -44.395 | 11.286 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| Operating Margin us-gaap:StatementBusinessSegments rily:CapitalMarketsSegment | ▁█ | 146.811 | 225.911 | NA | 134.742 | 134.096 | 94.248 | 85.301 | NA | NA | NA | 60.329 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| Operating Margin us-gaap:StatementBusinessSegments rily:PrincipalInvestmentsUnitedOnlineAndMagicJackSegment | ▄ | 21.602 | NA | NA | 23.686 | 23.863 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| SG&A Ratio us-gaap:StatementBusinessSegments rily:AuctionAndLiquidationSegment | █▁ | 44.185 | 8.251 | NA | -44.395 | 11.286 | 34.916 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| SG&A Ratio us-gaap:StatementBusinessSegments rily:CapitalMarketsSegment | ▁█ | 146.811 | 225.911 | NA | 134.742 | 134.096 | 94.248 | 85.301 | NA | NA | NA | 60.329 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| SG&A Ratio us-gaap:StatementBusinessSegments rily:PrincipalInvestmentsUnitedOnlineAndMagicJackSegment | █▁ | 21.602 | 21.431 | NA | 23.686 | 23.863 | 25.778 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 |
|---|
| 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:ComprehensiveIncomeNetOfTax | ▇█▁▅▆▆▅▄▅▅▅▅▅▅▅▅▅▅▅▅▅▅▅▅▅ | 48.905 | 84.355 | -99.885 | 17.486 | 33.781 | 22.324 | 8.193 | -9.27 | 2.737 | 16.132 | 4.283 | -6.326 | 0.713 | 3.681 | 14.666 | 11.826 | 8.916 | -0.183 | 0.313 | -1.127 | 1.184 | 8.735 | 1.898 | -0.599 | 0.671 |
| us-gaap:ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest | ▂▁▁▂▂▂▂▂▂▂▂▂▂▂▂█▁▂▂▂▂▂▂▂▂ | 0.513 | -1.311 | -0.584 | 0.387 | -0.158 | 0.152 | -0.044 | -0.16 | -0.092 | 0.804 | 0.339 | 0.662 | -0.246 | 0.083 | -0.12 | 10.569 | -0.565 | 0.074 | 1.122 | -0.042 | 1.155 | -0.095 | 0.194 | -0.22 | 0.845 |
| us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest | ▇█▁▆▆▆▅▄▅▅▅▅▅▅▅▆▅▅▅▅▅▅▅▅▅ | 49.418 | 83.044 | -100.469 | 17.873 | 33.623 | 22.476 | 8.149 | -9.43 | 2.645 | 16.936 | 4.622 | -5.664 | 0.467 | 3.764 | 14.546 | 22.395 | 8.351 | -0.109 | 1.435 | -1.169 | 2.339 | 8.64 | 2.092 | -0.819 | 1.516 |
| us-gaap:CostOfGoodsAndServicesSold us-gaap:StatementBusinessSegments rily:AuctionAndLiquidationSegment | █▁ | 9.046 | 0.285 | NA | 3.024 | 0.126 | 0.852 | -0.014 | NA | NA | NA | -0.001 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:CostOfGoodsAndServicesSold us-gaap:StatementBusinessSegments rily:PrincipalInvestmentsUnitedOnlineAndMagicJackSegment | █▁ | 0.767 | 0.575 | NA | 0.716 | 0.785 | 0.953 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:GainsLossesOnExtinguishmentOfDebt | NA | NA | 1.556 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:IncomeLossFromContinuingOperations | ▇█▁▆▆▆▅▄▅▅▅▅▅▅▅▆▅▅▅▅▅▅▅▅▅ | 67.603 | 114.737 | -136.788 | 25.358 | 48.553 | 31.598 | 11.083 | -12.474 | 4.768 | 23.178 | 5.831 | 10.812 | -1.235 | 0.816 | 10.052 | 31.146 | 14.457 | -0.092 | 0.248 | -1.418 | 1.463 | 8.664 | 4.125 | -1.142 | 1.521 |
| us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest us-gaap:StatementBusinessSegments us-gaap:CorporateAndOther | ▁█ | 67.603 | 114.737 | NA | 25.358 | 48.553 | 31.598 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments | ▁█ | 67.603 | 114.737 | NA | 25.358 | 48.553 | 31.598 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 1.536 | -1.418 | 3.218 | 14.254 | 4.125 | -1.142 | 1.521 |
| us-gaap:IncomeTaxExpenseBenefit | ▇█▁▄▆▆▅▃▅▅▅▃▅▅▄▄▅▅▅▅▅▅▅▅▅ | 18.711 | 32.208 | -37.539 | -7.842 | 14.409 | 9.289 | 3.104 | -13.052 | 2.046 | 5.377 | 0.989 | -16.263 | -1.357 | -2.547 | -3.849 | -8.137 | 6.083 | -0.065 | 0.166 | 0.372 | 0.6 | 5.685 | 1.549 | -0.375 | 0.057 |
| us-gaap:IncomeTaxesPaidNet | ▄▄▄▄▄▄▄▄▄▄▄█▁▆▄▄▄▄▄▄▄ | 0.852 | 1.182 | -0.574 | -3.62 | -4.138 | -0.699 | -0.192 | -4.042 | -0.149 | -2.17 | -0.136 | 26.654 | -21.357 | 9.618 | 0.071 | 0.276 | 0.0 | 0.04 | 0.369 | 0.712 | 0.281 | NA | NA | NA | NA |
| us-gaap:InterestExpense | ███▇▆▆▆▅▅▅▃▂▂▂▁▁▁▁▁▁▁▁▁▁▁ | 16.374 | 16.509 | 15.654 | 15.075 | 12.772 | 11.588 | 10.77 | 9.467 | 9.34 | 10.359 | 4.227 | 3.187 | 2.51 | 1.894 | 0.791 | 0.598 | 0.991 | 0.275 | 0.132 | 0.099 | 0.064 | 0.418 | 0.661 | 0.678 | 0.646 |
| us-gaap:InterestExpenseDebt | ▃▃▃█▃▁▂▅▁▁ | 15.563 | 15.588 | 14.392 | 43.823 | 11.255 | 0.063 | 8.875 | 25.428 | 1.103 | 1.618 | NA | 6.39 | 0.168 | 0.668 | 0.027 | NA | 0.813 | 0.251 | 0.023 | 0.0 | 0.022 | 0.175 | NA | NA | NA |
| us-gaap:InterestIncomeOperating | ▁▁▁▁▁▁▁▁▁▁▁█▁▁▁▁▁▁▁▁▁▁▁▁▁ | 0.067 | 0.224 | 0.246 | 0.248 | 0.361 | 0.331 | 0.637 | 0.59 | 0.442 | 0.166 | 0.128 | 16.67 | 0.076 | 0.15 | 0.132 | 0.286 | 0.026 | 0.003 | 0.003 | 0.007 | 0.005 | 0.003 | 0.0 | 0.089 | 0.331 |
| us-gaap:InterestPaidNet | █▇▆▆▆▄▅▅▄▄▃▃▃▁▁▁ | 29.297 | 24.149 | 21.785 | 22.694 | 21.327 | 14.169 | 17.435 | 14.814 | 13.421 | 12.86 | 9.008 | 7.327 | 8.623 | 1.504 | 1.386 | -0.129 | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:NetIncomeLoss | ▇█▁▅▆▆▅▄▅▅▅▅▅▅▅▅▅▅▅▅▅▅▅▅▅ | 48.379 | 83.84 | -98.665 | 17.129 | 34.302 | 22.157 | 8.023 | -8.805 | 2.814 | 16.997 | 4.503 | -6.113 | 0.368 | 3.28 | 14.021 | 12.44 | 8.939 | -0.101 | 0.248 | -1.004 | 1.463 | 8.664 | 2.382 | -0.547 | 0.619 |
| us-gaap:NetIncomeLossAttributableToNoncontrollingInterest | ▂▁▁▂▂▂▂▂▂▂▂▂▂▂▂█▁▂▂▂▂▂▂▂▁ | 0.513 | -1.311 | -0.584 | 0.387 | -0.158 | 0.152 | -0.044 | -0.16 | -0.092 | 0.804 | 0.339 | 0.662 | -0.246 | 0.083 | -0.12 | 10.569 | -0.565 | 0.074 | 1.122 | -0.042 | 1.155 | -0.095 | 0.194 | -0.22 | -0.845 |
| us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic | ▇█▁▅▆▆▅ | 47.291 | 82.753 | -99.72 | 16.865 | 34.302 | 22.157 | 8.023 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted | ▇█▁ | 47.291 | 82.753 | -99.72 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:OperatingExpenses | ██▇▇▇▇▇▆▅▅▅▅▅▄▂▃▂▁▁▁▁▂ | 142.752 | 135.128 | 120.938 | 127.67 | 120.212 | 120.429 | 117.15 | 108.565 | 86.843 | 97.023 | 85.176 | 95.96 | 91.07 | 64.116 | 42.186 | 61.72 | 41.544 | 20.081 | 18.281 | 21.087 | 17.995 | 30.792 | NA | NA | NA |
| us-gaap:OperatingIncomeLoss | ▇█▁▅▆▆▅▄▅▅▅▅▄▄▅▅▅▄▄▄▄▅▄▄▄ | 83.501 | 131.34 | -121.144 | 37.567 | 59.851 | 44.255 | 24.978 | -6.534 | 12.838 | 28.478 | 10.602 | 14.217 | 1.356 | 2.56 | 10.711 | 31.458 | 15.422 | 0.18 | 1.665 | -1.326 | 3.277 | 14.669 | 4.936 | -0.659 | 0.764 |
| us-gaap:OtherComprehensiveIncomeLossNetOfTax | ██▁▇▄▆▆▄▅▂▅▅▇▇█▃▅▅▆▅▅▆▄▅▆ | 0.526 | 0.515 | -1.22 | 0.357 | -0.521 | 0.167 | 0.17 | -0.465 | -0.077 | -0.865 | -0.22 | -0.213 | 0.345 | 0.401 | 0.645 | -0.614 | -0.023 | -0.082 | 0.065 | -0.123 | -0.279 | 0.071 | -0.484 | -0.052 | 0.052 |
| us-gaap:ProfitLoss | ▇█▁▅▆▆▅▄▅▆▅▅▅▅▅▆▅▅▅▅▅▅▅▅▅ | 48.892 | 82.529 | -99.249 | 17.516 | 34.144 | 22.309 | 7.979 | -8.965 | 2.722 | 17.801 | 4.842 | -5.451 | 0.122 | 3.363 | 13.901 | 23.009 | 8.374 | -0.027 | 1.37 | -1.046 | 2.618 | 8.569 | 2.576 | -0.767 | 1.464 |
| us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax | ▇▆▁█▆▇▅▅▅▅▅▆▅▄▃▅▃▂▂▂▂▃▂▂▂ | 150.965 | 121.696 | -0.206 | 165.237 | 111.855 | 138.918 | 103.095 | 102.031 | 88.944 | 104.686 | 86.274 | 110.177 | 92.426 | 66.676 | 52.897 | 93.178 | 56.966 | 20.261 | 19.946 | 19.761 | 21.272 | 45.461 | 30.73 | 14.235 | 19.651 |
| us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax | ▇▆▁█▆▇▇▅▅▆▅▆▅▄▃▅▃▂▂▂▂▃▂▂▂ | 150.965 | 121.696 | -0.206 | 165.237 | 111.855 | 138.918 | 142.128 | 102.031 | 99.681 | 125.501 | 95.778 | 110.177 | 92.426 | 66.676 | 52.897 | 93.178 | 56.966 | 20.261 | 19.946 | 19.761 | 21.272 | 45.461 | 30.73 | 14.235 | 19.651 |
| us-gaap:Revenues | ▇█▁▅▆▅▅▄▄▄▄▄▃▃▂▃▃▂▂▂▂▂▂▁▂ | 226.253 | 266.468 | -0.206 | 165.237 | 180.063 | 164.684 | 142.128 | 102.031 | 99.681 | 125.501 | 95.778 | 110.177 | 92.426 | 66.676 | 52.897 | 93.178 | 56.966 | 20.261 | 19.946 | 19.761 | 21.272 | 45.461 | 30.73 | 14.235 | 19.651 |
| us-gaap:SellingGeneralAndAdministrativeExpense | ▇█▆█▇▆▇▆▅▆▅▆▅▃▂▃▂▁▁▁▁▂▁▁▁ | 97.143 | 106.562 | 87.744 | 110.751 | 96.587 | 87.338 | 90.543 | 77.079 | 71.782 | 76.723 | 68.098 | 80.172 | 70.962 | 37.722 | 24.152 | 33.283 | 22.727 | 14.521 | 11.596 | 12.567 | 12.782 | 20.072 | 13.679 | 7.878 | 9.758 |
| 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 |
|---|
| 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:Assets | ██▇█▇▇▇▇▇▇▅▅▅▅▂▂▂▁▁▁▁▁▁▁▁ | 2300.082 | 2295.272 | 2130.896 | 2318.178 | 2106.891 | 1978.983 | 1917.986 | 1957.71 | 1920.901 | 1877.169 | 1430.329 | 1386.904 | 1226.077 | 1341.42 | 254.933 | 264.618 | 261.354 | 169.538 | 126.147 | 132.42 | 142.369 | 147.345 | 80.583 | 72.862 | 74.995 |
| us-gaap:Liabilities | ████▇▇▇▇▇▇▅▅▄▅▁▁▁▁▁▁▁▁▁▁▁ | 1900.101 | 1959.053 | 1867.875 | 1927.927 | 1807.487 | 1701.805 | 1654.061 | 1699.05 | 1651.755 | 1612.893 | 1158.664 | 1121.058 | 951.44 | 1101.341 | 92.928 | 114.226 | 117.76 | 35.136 | 14.955 | 23.1 | 29.37 | 34.174 | 84.758 | 79.131 | 80.47 |
| us-gaap:LiabilitiesAndStockholdersEquity | ██▇█▇▇▇▇▇▇▅▅▅▅▂▂▂▁▁▁▁▁▁▁▁ | 2300.082 | 2295.272 | 2130.896 | 2318.178 | 2106.891 | 1978.983 | 1917.986 | 1957.71 | 1920.901 | 1877.169 | 1430.329 | 1386.904 | 1226.077 | 1341.42 | 254.933 | 264.618 | 261.354 | 169.538 | 126.147 | 132.42 | 142.369 | 147.345 | 80.583 | 72.862 | 74.995 |
| us-gaap:StockholdersEquity | █▇▅█▇▆▆▆▆▆▆▆▆▆▄▄▄▄▃▃▃▃▁▁▁ | 373.859 | 310.009 | 235.035 | 360.66 | 298.852 | 276.468 | 263.367 | 258.058 | 268.384 | 263.422 | 271.543 | 266.03 | 274.684 | 239.018 | 161.051 | 149.347 | 142.503 | 133.324 | 110.188 | 109.438 | 111.167 | 112.494 | -5.103 | -7.001 | -6.402 |
| 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:CashAndCashEquivalentsAtCarryingValue | ▆▄▄▄▆▂▆▆█▇▃▅▄▄▃▄▁▂▁▁▂▂▁▁▁ | 169.676 | 106.253 | 124.231 | 104.268 | 170.587 | 55.609 | 163.462 | 179.44 | 233.918 | 191.274 | 74.339 | 132.823 | 102.409 | 104.67 | 71.541 | 112.105 | 26.474 | 48.123 | 26.786 | 30.012 | 45.922 | 42.128 | 18.721 | 18.987 | 23.435 |
| us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents | ▅▃▄▃▅▁▅▆█▆▃▅▃▃ | 171.086 | 106.724 | 124.702 | 104.739 | 171.058 | 58.244 | 170.953 | 180.278 | 234.386 | 191.741 | 97.71 | 152.534 | 111.678 | 110.302 | NA | 115.399 | NA | NA | NA | 30.063 | NA | NA | NA | NA | NA |
| us-gaap:AccountsReceivableNetCurrent | ▇▆▇▇▇█▆▆▆▅▄▃▃▃▃▃▂▁▁▂▂▃▂▁▁ | 45.654 | 43.226 | 46.45 | 46.624 | 47.419 | 56.45 | 43.975 | 42.123 | 38.958 | 33.111 | 25.382 | 20.015 | 19.924 | 19.319 | 18.022 | 18.989 | 15.112 | 7.997 | 7.945 | 9.472 | 10.069 | 23.424 | 16.591 | 6.148 | 5.816 |
| us-gaap:PrepaidExpenseAndOtherAssetsCurrent | ▅▆▇▅▇█▅▅▃▃▃▂▂▂▁▁▁▁▁▁▁▁▁▁▁ | 87.56 | 105.312 | 114.686 | 81.808 | 112.309 | 140.817 | 87.942 | 79.477 | 50.193 | 42.203 | 39.468 | 22.605 | 20.375 | 10.986 | 3.592 | 3.578 | 4.543 | 8.507 | 2.993 | 2.415 | 1.351 | 1.229 | 1.145 | 1.175 | 0.961 |
| 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:NoncurrentAssets us-gaap:StatementGeographical srt:NorthAmerica | ▂▃▃▃▄▅██▁▁ | 11.986 | 12.287 | 12.223 | 12.727 | 13.171 | 13.997 | 15.634 | 15.489 | 11.143 | 11.195 | NA | 11.977 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:PropertyPlantAndEquipmentGross | NA | NA | NA | 31.233 | NA | NA | NA | 35.308 | NA | NA | NA | 19.996 | NA | NA | NA | 10.805 | NA | NA | NA | 4.259 | NA | NA | 3.691 | NA | NA | |
| us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType rily:MachineryEquipmentAndComputerSoftware | NA | NA | NA | 14.873 | NA | NA | NA | 18.652 | NA | NA | NA | 9.474 | NA | NA | NA | 6.559 | NA | NA | NA | 2.4 | NA | NA | NA | NA | NA | |
| us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType us-gaap:FurnitureAndFixtures | NA | NA | NA | 4.305 | NA | NA | NA | 5.143 | NA | NA | NA | 2.688 | NA | NA | NA | 1.921 | NA | NA | NA | 1.16 | NA | NA | 0.974 | NA | NA | |
| us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType us-gaap:LeaseholdImprovements | NA | NA | NA | 12.055 | NA | NA | NA | 11.513 | NA | NA | NA | 7.834 | NA | NA | NA | 2.325 | NA | NA | NA | 0.311 | NA | NA | 0.282 | NA | NA | |
| us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment | NA | NA | NA | 18.506 | NA | NA | NA | 19.785 | NA | NA | NA | 8.019 | NA | NA | NA | 5.02 | NA | NA | NA | 3.667 | NA | NA | 2.721 | 0.095 | 0.048 | |
| us-gaap:PropertyPlantAndEquipmentNet | ▆▆▆▇▇▇██▆▆▆▆▇▇▃▃▃▁▁▁▁▁▁▁▁ | 11.986 | 12.287 | 12.223 | 12.727 | 13.171 | 13.997 | 15.644 | 15.523 | 11.143 | 11.195 | 11.467 | 11.977 | 13.105 | 13.45 | 5.409 | 5.785 | 5.765 | 0.475 | 0.519 | 0.592 | 0.651 | 0.729 | 0.97 | 0.897 | 0.96 |
| us-gaap:Goodwill | ████████▅▄▄▄▄▃▂▂▂▂▂▂▂▂▁▁▁ | 227.046 | 227.046 | 223.697 | 223.697 | 220.562 | 220.181 | 223.243 | 223.368 | 120.129 | 99.246 | 98.771 | 98.771 | 100.903 | 67.335 | 48.903 | 48.903 | 52.634 | 34.528 | 34.528 | 34.528 | 34.528 | 34.528 | 5.688 | 5.688 | 5.688 |
| us-gaap:IntangibleAssetsNetExcludingGoodwill | ▇▇██▄▄▄▄▃▃▃▃▃▂▂▂▂▁▁▁▁▁▁▁▁ | 194.516 | 199.991 | 212.5 | 220.525 | 79.488 | 82.765 | 88.479 | 91.358 | 51.011 | 52.603 | 54.788 | 56.948 | 59.671 | 45.033 | 39.239 | 41.166 | 40.913 | 4.545 | 4.656 | 4.768 | 4.88 | 4.991 | 0.14 | 0.14 | 0.14 |
| us-gaap:FiniteLivedIntangibleAssetsNet | ▅▆▆▇▆▇██▃▃▃▃▄▂▁▁▁ | 69.24 | 74.075 | 78.084 | 82.109 | 77.248 | 80.525 | 88.479 | 91.358 | 51.011 | 52.603 | 54.788 | 56.948 | 59.672 | 45.033 | 39.239 | 41.166 | 39.173 | NA | NA | 3.028 | NA | NA | NA | NA | NA |
| us-gaap:DeferredTaxAssetsLiabilitiesNet | NA | NA | NA | 31.522 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| us-gaap:OperatingLeaseRightOfUseAsset | ▁▂▃▅▇██ | 43.514 | 44.636 | 46.213 | 47.809 | 49.642 | 50.943 | 51.086 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:AccountsPayableCurrent | ▅▅█▅▇▂▆▇▂▄▄▃▅▄▃▃▅▁▁▁ | 4.226 | 4.301 | 6.858 | 4.477 | 6.239 | 2.136 | 5.217 | 5.646 | 2.278 | 3.79 | 3.18 | 2.65 | 4.046 | 3.184 | 2.498 | 2.703 | 4.188 | 1.084 | 1.466 | 1.123 | NA | NA | NA | NA | NA |
| us-gaap:OtherAccruedLiabilitiesCurrent | █▇▆█▇▆▆▇▆▅▄▅▄▄▂▂▂▁▁▁ | 127.036 | 106.531 | 103.452 | 130.714 | 115.062 | 93.832 | 90.921 | 108.662 | 87.901 | 72.986 | 57.746 | 71.685 | 58.954 | 62.573 | 18.389 | 18.505 | 18.279 | 5.335 | 5.314 | 6.478 | NA | NA | NA | NA | NA |
| 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:MinorityInterest | ▇▇██▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁ | 26.122 | 26.21 | 27.986 | 29.591 | 0.552 | 0.71 | 0.558 | 0.602 | 0.762 | 0.854 | 0.122 | -0.184 | -0.047 | 1.061 | 0.954 | 1.045 | 1.091 | 1.078 | 1.004 | -0.118 | 1.832 | 0.677 | 0.928 | 0.732 | 0.927 |
| 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:StockholdersEquity | █▇▅█▇▆▆▆▆▆▆▆▆▆▄▄▄▄▃▃▃▃▁▁▁ | 373.859 | 310.009 | 235.035 | 360.66 | 298.852 | 276.468 | 263.367 | 258.058 | 268.384 | 263.422 | 271.543 | 266.03 | 274.684 | 239.018 | 161.051 | 149.347 | 142.503 | 133.324 | 110.188 | 109.438 | 111.167 | 112.494 | -5.103 | -7.001 | -6.402 |
| us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest | █▇▆█▆▆▆▆▆▆▆▆▆▅▄▄▄▃▃▃▃▃▁▁▁ | 399.981 | 336.219 | 263.021 | 390.251 | 299.404 | 277.178 | 263.925 | 258.66 | 269.146 | 264.276 | 271.665 | 265.846 | 274.637 | 240.079 | 162.005 | 150.392 | 143.594 | 134.402 | 111.192 | 109.32 | 112.999 | 113.171 | -4.175 | -6.269 | -5.475 |
| us-gaap:CommonStockValue | ▄▄▄▄▄▄▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁███ | 0.003 | 0.003 | 0.003 | 0.003 | 0.003 | 0.003 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.004 | 0.004 | 0.004 |
| us-gaap:AdditionalPaidInCapital | █▇▇█▆▆▆▆▆▆▆▆▆▆▄▄▄▄▃▃▃▃▁▁▁ | 332.085 | 306.772 | 308.472 | 323.109 | 259.237 | 255.865 | 257.888 | 258.638 | 255.236 | 244.631 | 261.413 | 259.98 | 259.047 | 220.628 | 143.228 | 141.17 | 141.389 | 140.555 | 117.236 | 116.799 | 116.423 | 115.671 | 3.082 | 3.082 | 3.082 |
| us-gaap:RetainedEarningsAccumulatedDeficit | █▆▁██▇▆▅▆▇▆▆▆▆▆▆▅▅▅▅▅▅▅▅▅ | 43.938 | 5.927 | -70.232 | 39.536 | 41.957 | 22.424 | 7.468 | 1.579 | 14.842 | 20.408 | 10.882 | 6.582 | 15.956 | 19.054 | 18.888 | 9.887 | 2.21 | -6.158 | -6.057 | -6.305 | -4.323 | -2.523 | -7.669 | -10.051 | -9.504 |
| us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax | ▃▂▁▄▃▄▄▃▄▄▆▇▇▇▆▄▆▆▆▆▆▇▇██ | -2.167 | -2.693 | -3.208 | -1.988 | -2.345 | -1.824 | -1.991 | -2.161 | -1.696 | -1.619 | -0.754 | -0.534 | -0.321 | -0.666 | -1.067 | -1.712 | -1.098 | -1.075 | -0.993 | -1.058 | -0.935 | -0.656 | -0.52 | -0.036 | 0.016 |
| us-gaap:MinorityInterest | ▇▇██▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁ | 26.122 | 26.21 | 27.986 | 29.591 | 0.552 | 0.71 | 0.558 | 0.602 | 0.762 | 0.854 | 0.122 | -0.184 | -0.047 | 1.061 | 0.954 | 1.045 | 1.091 | 1.078 | 1.004 | -0.118 | 1.832 | 0.677 | 0.928 | 0.732 | 0.927 |
| us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue | ▇▆██▇▄▄▆▅▄▄▄▅▄▂▂▂▁▁▂▁ | 4.778 | 4.168 | 5.321 | 5.64 | 4.728 | 2.934 | 2.614 | 4.392 | 3.091 | 3.001 | 2.558 | 2.662 | 3.739 | 3.033 | 0.907 | 0.937 | 0.834 | 0.56 | 0.437 | 0.91 | 0.752 | NA | NA | NA | NA |
| us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders | █▁ | 0.601 | 0.465 | NA | NA | NA | NA | NA | NA | NA | NA | NA | 0.0 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:NetCashProvidedByUsedInOperatingActivities | ▇▅▅▃▆▅▅▄█▁▃▄▆▄▄▆ | 73.465 | 12.977 | 0.455 | -76.615 | 44.785 | -7.486 | 8.924 | -25.919 | 129.871 | -154.711 | -54.055 | -33.011 | 34.041 | -43.965 | -38.855 | 52.354 | NA | NA | NA | NA | NA | NA | 0.633 | 1.638 | 6.431 |
| us-gaap:NetCashProvidedByUsedInInvestingActivities | ▆▆▄▅▅▁▅▃▅▆▆▆▅▆▆█▄▆▆▆▆ | -15.989 | -11.065 | -71.492 | -43.952 | -23.868 | -201.063 | -26.513 | -104.892 | -42.87 | 0.589 | -4.268 | -10.706 | -30.271 | 4.235 | 3.12 | 75.001 | -99.789 | -12.065 | -0.019 | 0.028 | 0.353 | NA | -1.318 | -3.682 | -1.363 |
| us-gaap:NetCashProvidedByUsedInFinancingActivities | ▂▂▄▃▄▄▂▄▁█▂▄▂▄▂▁▄▃▂▂▂ | 5.774 | -20.517 | 92.332 | 53.992 | 92.117 | 95.826 | 8.241 | 76.767 | -44.059 | 248.338 | 3.813 | 75.375 | -7.032 | 72.592 | -6.841 | -39.982 | 60.59 | 21.983 | -2.187 | -3.496 | -3.72 | NA | 0.572 | -2.824 | -2.157 |
| us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect | ▄ | 64.362 | NA | NA | -66.319 | 112.814 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:DeferredIncomeTaxExpenseBenefit | █▁▂▃▃▄▃▃▃ | 31.652 | -10.086 | -4.254 | 4.516 | -0.072 | 6.82 | -0.39 | 1.983 | 0.0 | NA | NA | 29.222 | -0.924 | -14.512 | -9.124 | 1.71 | 1.568 | 0.119 | 0.152 | 1.158 | -0.048 | 3.789 | 1.478 | -0.266 | -0.424 |
| us-gaap:DepreciationDepletionAndAmortization | ████▇██▇▅▆▆▆▆▄▄▄▄▁▂▁▂▁▂▂▂ | 4.886 | 4.923 | 4.956 | 4.831 | 4.473 | 4.831 | 4.913 | 4.041 | 3.098 | 3.333 | 3.337 | 3.435 | 3.415 | 2.248 | 2.042 | 1.925 | 1.982 | 0.084 | 0.203 | -0.217 | 0.213 | 0.11 | 0.158 | 0.153 | 0.161 |
| us-gaap:IncreaseDecreaseInAccountsReceivable | ▄▄▄▅▄▅▄▄▁█▄ | 2.265 | -11.927 | -15.674 | 25.282 | -13.775 | 19.575 | 2.845 | -23.034 | -172.676 | 200.58 | 8.078 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:NetCashProvidedByUsedInOperatingActivities | ▇▅▅▃▆▅▅▄█▁▃▄▆▄▄▆ | 73.465 | 12.977 | 0.455 | -76.615 | 44.785 | -7.486 | 8.924 | -25.919 | 129.871 | -154.711 | -54.055 | -33.011 | 34.041 | -43.965 | -38.855 | 52.354 | NA | NA | NA | NA | NA | NA | 0.633 | 1.638 | 6.431 |
| us-gaap:NetIncomeLoss | ▇█▁▅▆▆▅▄▅▅▅▅▅▅▅▅▅▅▅▅▅▅▅▅▅ | 48.379 | 83.84 | -98.665 | 17.129 | 34.302 | 22.157 | 8.023 | -8.805 | 2.814 | 16.997 | 4.503 | -6.113 | 0.368 | 3.28 | 14.021 | 12.44 | 8.939 | -0.101 | 0.248 | -1.004 | 1.463 | 8.664 | 2.382 | -0.547 | 0.619 |
| us-gaap:ProfitLoss | ▇█▁▅▆▆▅▄▅▆▅▅▅▅▅▆▅▅▅▅▅▅▅▅▅ | 48.892 | 82.529 | -99.249 | 17.516 | 34.144 | 22.309 | 7.979 | -8.965 | 2.722 | 17.801 | 4.842 | -5.451 | 0.122 | 3.363 | 13.901 | 23.009 | 8.374 | -0.027 | 1.37 | -1.046 | 2.618 | 8.569 | 2.576 | -0.767 | 1.464 |
| us-gaap:ShareBasedCompensation | ▇▆██▇▄▄▆▅▄▄▄▅▄▂▂▂▁▁▂▁ | 4.778 | 4.167 | 5.322 | 5.64 | 4.728 | 2.934 | 2.614 | 4.392 | 3.091 | 3.001 | 2.558 | 2.662 | 3.739 | 3.033 | 0.907 | 0.937 | 0.834 | 0.56 | 0.437 | 0.851 | 0.776 | NA | 0.0 | 0.0 | NA |
| 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:NetCashProvidedByUsedInInvestingActivities | ▆▆▄▅▅▁▅▃▅▆▆▆▅▆▆█▄▆▆▆▆ | -15.989 | -11.065 | -71.492 | -43.952 | -23.868 | -201.063 | -26.513 | -104.892 | -42.87 | 0.589 | -4.268 | -10.706 | -30.271 | 4.235 | 3.12 | 75.001 | -99.789 | -12.065 | -0.019 | 0.028 | 0.353 | NA | -1.318 | -3.682 | -1.363 |
| 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:NetCashProvidedByUsedInFinancingActivities | ▂▂▄▃▄▄▂▄▁█▂▄▂▄▂▁▄▃▂▂▂ | 5.774 | -20.517 | 92.332 | 53.992 | 92.117 | 95.826 | 8.241 | 76.767 | -44.059 | 248.338 | 3.813 | 75.375 | -7.032 | 72.592 | -6.841 | -39.982 | 60.59 | 21.983 | -2.187 | -3.496 | -3.72 | NA | 0.572 | -2.824 | -2.157 |
| us-gaap:PaymentsOfDividendsCommonStock | ▄▄▅█▇▃▁ | 8.333 | 7.88 | 9.609 | 16.089 | 15.058 | 7.385 | 2.606 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:PaymentsForRepurchaseOfCommonStock | ▄▂█▁▁▁▂▁▁ | 10.569 | 3.711 | 24.068 | 0.0 | 1.021 | 0.602 | 2.65 | 1.365 | 0.0 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:ConsolidatedEntities,us-gaap:DebtInstrument,us-gaap:TypeOfArrangement rily:BRPIAcquisitionCoLLC,rily:TermLoan,rily:BRPACCreditAgreement | █▁▁▁▁▁▁▁ | 2.8999999999999998e-06 | 2.93e-08 | 3.7400000000000004e-08 | 4.55e-08 | 5.05e-08 | 5.4899999999999995e-08 | 5.5e-08 | 5.5100000000000004e-08 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:DebtInstrument rily:SeniorNotes1 | █▁ | 7.5e-06 | 7.5e-08 | NA | NA | NA | 7.5e-08 | 7.5e-08 | 7.5e-08 | 7.5e-08 | 7.5e-08 | 7.5e-08 | 7.5e-08 | 7.5e-08 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:DebtInstrument rily:SeniorNotes4 | █▁ | 7.25e-06 | 7.25e-08 | NA | NA | NA | 7.25e-08 | 7.25e-08 | 7.25e-08 | 7.25e-08 | 7.25e-08 | 7.25e-08 | 7.25e-08 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:DebtInstrument rily:SeniorNotes5 | █▁ | 7.375e-06 | 7.375e-08 | NA | NA | NA | 7.25e-08 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:DebtInstrument rily:SeniorNotes7 | █▁ | 6.875e-06 | 6.875e-08 | NA | NA | NA | 6.875e-08 | 6.875e-08 | 6.875e-08 | 6.875e-08 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:DebtInstrument rily:SeniorNotesEight | █▁ | 6.375e-06 | 6.375e-08 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:DebtInstrument rily:SeniorNotesSeven | █▁ | 6.5e-06 | 6.5e-08 | 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:DebtInstrument rily:SixPointSevenFivePercentSeniorNotes | █▁▁ | 6.75e-06 | 6.75e-08 | 6.75e-08 | 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:DebtInstrument,us-gaap:SubsequentEventType rily:SeniorNotesTwentyTwentyEight,us-gaap:SubsequentEvent | NA | 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 | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 3000.0 | 3000.0 | 3000.0 | 3000.0 | 3000.0 | 3000.0 | 3000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 |
| 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 |
| 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 |
| 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 | 2011-03-31 |
| Value | 6.72 | 1.86 | 3.23 | -3.83 | 0.64 | 1.29 | 0.84 | 0.31 | -0.34 | 0.11 | 0.67 | 0.17 | -0.23 | 0.01 | 0.15 | 0.73 | 0.65 | 0.47 | -0.01 | 0.02 | -0.06 | 0.09 | 0.53 | 0.17 | -0.18 | -0.05 | -0.16 | -0.05 | 0.03 | 0.01 | -0.05 | 0.04 | 0.08 | -0.02 | 0.02 | 0.04 | -0.02 | 0.14 | -0.08 | -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 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 57.35 | 1.75 | 3.07 | -3.83 | 0.59 | 1.21 | 0.82 | 0.3 | -0.34 | 0.1 | 0.64 | 0.17 | -0.23 | 0.01 | 0.15 | 0.71 | 0.64 | 0.47 | -0.01 | 0.01 | -0.06 | 0.09 | 0.53 | 0.17 | -0.18 | -0.05 | -0.16 | -0.05 | 0.03 | 0.01 | -0.05 | 0.04 | 0.08 | -0.02 | 0.02 | 0.04 | -0.02 | 0.14 | -0.08 | -0.02 | -0.06 | 0.02 | -0.24 |
| Percentage of EarningsPerShareDiluted | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2019-09-30 |
| Value | 1.86 | 1.29 |
| Percentage of IncomeLossFromContinuingOperationsPerBasicShare | 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 | 2011-03-31 |
| Value | 172 | 48 | 84 | -99.885 | 17 | 33 | 22 | 8.193 | -9.27 | 2.737 | 16 | 4.283 | -6.326 | 0.713 | 3.681 | 14 | 11 | 8.916 | -0.183 | 0.313 | -1.127 | 1.184 | 8.735 | 2.603 | -2.843 | -0.837 | -0.773 | -1.358 | 1.105 | 0.303 | -1.402 | 0.934 | 1.898 | -0.599 | 0.671 | 1.278 | -0.814 | 4.067 | -2.359 | -0.546 |
| 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 |
| Percentage of InterestIncomeOperating | 0.0 | 72992.5 | 37658.5 | -40603.7 | 0.0 | 9357.6 | 6744.4 | 1286.2 | 0.0 | 619.2 | 9718.1 | 3346.1 | 0.0 | 938.2 | 2454.0 | 11110.6 | 0.0 | 34292.3 | -6100.0 | 10433.3 | 0.0 | 23680.0 | 291166.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -673.0 | 202.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 | 0.251 | 0.513 | -1.311 | -0.584 | 0.387 | -0.158 | 0.152 | -0.044 | -0.16 | -0.092 | 0.804 | 0.339 | 0.662 | -0.246 | 0.083 | -0.12 | 10 | -0.565 | 0.074 | 1.122 | -0.042 | 1.155 | -0.095 | 0.754 | -0.08 | -0.048 | -0.13 | 0.264 | 0.066 | -0.13 | -0.064 | -0.354 | 0.194 | -0.22 | 0.845 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of InterestIncomeOperating | 0.0 | 765.7 | -585.3 | -237.4 | 0.0 | -43.8 | 45.9 | -6.9 | 0.0 | -20.8 | 484.3 | 264.8 | 0.0 | -323.7 | 55.3 | -90.9 | 0.0 | -2173.1 | 2466.7 | 37400.0 | 0.0 | 23100.0 | -3166.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -247.2 | 255.3 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 | 173 | 49 | 83 | -100.469 | 17 | 33 | 22 | 8.149 | -9.43 | 2.645 | 16 | 4.622 | -5.664 | 0.467 | 3.764 | 14 | 22 | 8.351 | -0.109 | 1.435 | -1.169 | 2.339 | 8.64 | 3.357 | -2.923 | -0.885 | -0.903 | -1.094 | 1.171 | 0.173 | -1.466 | 0.58 | 2.092 | -0.819 | 1.516 | 1.278 | -0.814 | 4.067 | -2.359 |
| Percentage of ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 InterestIncomeOperating | 0.0 | 73758.2 | 37073.2 | -40841.1 | 0.0 | 9313.9 | 6790.3 | 1279.3 | 0.0 | 598.4 | 10202.4 | 3610.9 | 0.0 | 614.5 | 2509.3 | 11019.7 | 0.0 | 32119.2 | -3633.3 | 47833.3 | 0.0 | 46780.0 | 288000.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -920.2 | 458.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-03-31 |
| Value | 0.406 | 9.046 | 0.285 | 3.024 | 0.126 | 0.852 | -0.014 | -0.001 |
| Percentage of CostOfGoodsAndServicesSold | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 13501.5 | 127.2 | 0.0 | 34.9 | 257.4 | -2.2 | -0.8 |
| Percentage of InterestIncomeOperating rily:AuctionAndLiquidationSegment | 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 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 0.612 | 0.767 | 0.575 | 0.716 | 0.785 | 0.953 |
| Percentage of CostOfGoodsAndServicesSold | 150.7 | 8.5 | 201.8 | 23.7 | 623.0 | 111.9 |
| Percentage of InterestIncomeOperating | 0.0 | 1144.8 | 256.7 | 0.0 | 217.5 | 287.9 |
| Percentage of InterestIncomeOperating rily:PrincipalInvestmentsUnitedOnlineAndMagicJackSegment | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-03-31 | 2014-12-31 |
| Value | 0.0 | 1.556 | 0.0 |
| Percentage of GainsLossesOnExtinguishmentOfDebt | 0.0 | 100.0 | 0.0 |
| Percentage of InterestIncomeOperating | 0.0 | 632.5 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 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 | 233 | 67 | 114 | -136.788 | 25 | 48 | 31 | 11 | -12.474 | 4.768 | 23 | 5.831 | 10 | -1.235 | 0.816 | 10 | 31 | 14 | -0.092 | 0.248 | -1.418 | 1.463 | 8.664 | 2.682 | -3.993 | -0.868 | -0.777 | -1.334 | 2.046 | 0.366 | -1.531 | 1.289 | 4.125 | -1.142 | 1.521 | 1.772 | -0.458 | 6.049 | -3.107 | 0.178 |
| Percentage of IncomeLossFromContinuingOperations | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 100900.0 | 51221.9 | -55604.9 | 0.0 | 13449.6 | 9546.2 | 1739.9 | 0.0 | 1078.7 | 13962.7 | 4555.5 | 0.0 | -1625.0 | 544.0 | 7615.2 | 0.0 | 55603.8 | -3066.7 | 8266.7 | 0.0 | 29260.0 | 288800.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -1283.1 | 459.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 233 | 67 | 114 | 25 | 48 | 31 |
| Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 100900.0 | 51221.9 | 0.0 | 13449.6 | 9546.2 |
| Percentage of InterestIncomeOperating us-gaap:CorporateAndOther | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 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 | 233 | 67 | 114 | 25 | 48 | 31 | 1.536 | -1.418 | 3.218 | 14 | 5.211 | -3.993 | -1.303 | -1.501 | -1.884 | 2.046 | 0.103 | -2.582 | 1.713 | 4.125 | -1.142 | 1.521 | 1.772 | -0.458 | 6.049 | -3.107 | 0.178 | -2.057 | 1.335 | -10.87 |
| Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 InterestIncomeOperating | 0.0 | 100900.0 | 51221.9 | 0.0 | 13449.6 | 9546.2 | 51200.0 | 0.0 | 64360.0 | 475133.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -1283.1 | 459.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 | 62 | 18 | 32 | -37.539 | -7.842 | 14 | 9.289 | 3.104 | -13.052 | 2.046 | 5.377 | 0.989 | -16.263 | -1.357 | -2.547 | -3.849 | -8.137 | 6.083 | -0.065 | 0.166 | 0.372 | 0.6 | 5.685 | 1.775 | 1.091 | -0.387 | -0.594 | -0.814 | -1.046 | -0.133 | -0.987 | 0.778 | 1.549 | -0.375 | 0.057 | 0.705 | 0.196 | 2.018 | -0.858 | 0.704 | -0.151 | 0.88 | -4.263 |
| 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 |
| Percentage of InterestIncomeOperating | 0.0 | 27926.9 | 14378.6 | -15259.8 | 0.0 | 3991.4 | 2806.3 | 487.3 | 0.0 | 462.9 | 3239.2 | 772.7 | 0.0 | -1785.5 | -1698.0 | -2915.9 | 0.0 | 23396.2 | -2166.7 | 5533.3 | 0.0 | 12000.0 | 189500.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -421.3 | 17.2 | 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 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 88 | -18.711 | -32.208 | 61 | -14.409 | -9.289 |
| Percentage of IncomeTaxExpenseBenefit | 143.1 | -100.0 | -100.0 | -783.6 | -100.0 | -100.0 |
| Percentage of InterestIncomeOperating | 0.0 | -27926.9 | -14378.6 | 0.0 | -3991.4 | -2806.3 |
| Percentage of InterestIncomeOperating us-gaap:CorporateAndOther | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 |
| Value | 0.908 | 0.852 | 1.182 | -0.574 | -3.62 | -4.138 | -0.699 | -0.192 | -4.042 | -0.149 | -2.17 | -0.136 | 26 | -21.357 | 9.618 | 0.071 | 0.276 | 0.0 | 0.04 | 0.369 | 0.712 | 0.281 |
| Percentage of IncomeTaxesPaidNet | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 1271.6 | 527.7 | -233.3 | 0.0 | -1146.3 | -211.2 | -30.1 | 0.0 | -33.7 | -1307.2 | -106.2 | 0.0 | -28101.3 | 6412.0 | 53.8 | 0.0 | 0.0 | 1333.3 | 12300.0 | 0.0 | 5620.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 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 | 16 | 16 | 15 | 15 | 12 | 11 | 10 | 9.467 | 9.34 | 10 | 4.227 | 3.187 | 2.51 | 1.894 | 0.791 | 0.598 | 0.991 | 0.275 | 0.132 | 0.099 | 0.064 | 0.418 | 0.253 | 0.132 | 0.053 | 0.449 | 0.628 | 0.829 | 0.567 | 0.637 | 0.634 | 0.661 | 0.678 | 0.646 | 0.627 | 1.011 | 2.921 | 0.625 | 0.328 | 1.027 | 0.848 | 0.759 |
| 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 |
| Percentage of InterestIncomeOperating | 24438.8 | 7370.1 | 6363.4 | 0.0 | 3538.0 | 3500.9 | 1690.7 | 0.0 | 2113.1 | 6240.4 | 3302.3 | 0.0 | 3302.6 | 1262.7 | 599.2 | 0.0 | 3811.5 | 9166.7 | 4400.0 | 0.0 | 1280.0 | 13933.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 761.8 | 195.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 |
| Value | 11 | 10 | 10 | 7.921 | 52 | -9.721 | 5.502 | 6.804 | 39 | -6.425 |
| Percentage of InterestExpense | 0.0 | 64.3 | 65.4 | 50.6 | 350.0 | -76.1 | 47.5 | 63.2 | 415.7 | -68.8 |
| Percentage of InterestIncomeOperating | 0.0 | 15716.4 | 4822.3 | 3219.9 | 0.0 | -2692.8 | 1662.2 | 1068.1 | 0.0 | -1453.6 |
| Percentage of InterestIncomeOperating us-gaap:FixedIncomeSecurities | 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 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | -16.712 | -16.374 | -16.509 | -15.075 | -12.772 | -11.588 |
| Percentage of InterestExpense | 0.0 | -100.0 | -100.0 | -100.0 | -100.0 | -100.0 |
| Percentage of InterestIncomeOperating | 0.0 | -24438.8 | -7370.1 | 0.0 | -3538.0 | -3500.9 |
| Percentage of InterestIncomeOperating us-gaap:CorporateAndOther | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 |
| Value | 19 | 15 | 15 | 14 | 43 | 11 | 0.063 | 8.875 | 25 | 1.103 | 1.618 | 6.39 | 0.168 | 0.668 | 0.027 | 0.813 | 0.251 | 0.023 | 0.0 | 0.022 | 0.175 | 0.146 | -0.117 | 0.028 | 0.089 |
| Percentage of InterestExpenseDebt | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 23228.4 | 6958.9 | 5850.4 | 0.0 | 3117.7 | 19.0 | 1393.2 | 0.0 | 249.5 | 974.7 | 0.0 | 221.1 | 445.3 | 20.5 | 3126.9 | 8366.7 | 766.7 | 0.0 | 440.0 | 5833.3 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 0.11 | 0.109 | 0.143 | 0.677 | 0.24 | 0.104 |
| Percentage of InterestExpenseDebt | 0.6 | 0.7 | 0.9 | 1.5 | 2.1 | 165.1 |
| Percentage of InterestIncomeOperating | 0.0 | 162.7 | 63.8 | 0.0 | 66.5 | 31.4 |
| Percentage of InterestIncomeOperating rily:WellsFargoBankNationalAssociation rily:AssetBasedCreditFacility100000 rily:SecondAmendedAndRestatedCreditAgreement | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 0.497 | 0.586 | 0.829 | 1.118 | 1.257 | 1.278 |
| Percentage of InterestExpenseDebt | 3.2 | 3.8 | 5.8 | 9.9 | 1995.2 | 14.4 |
| Percentage of InterestIncomeOperating | 741.8 | 261.6 | 337.0 | 309.7 | 379.8 | 200.6 |
| Percentage of InterestIncomeOperating rily:BRPIAcquisitionCoLLC rily:TermLoan rily:BRPACCreditAgreement | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 |
| Value | 15 | 15 | 11 | 10 |
| Percentage of InterestExpenseDebt | 100.0 | 100.0 | 100.0 | 15985.7 |
| Percentage of InterestIncomeOperating | 23226.9 | 6958.9 | 3117.7 | 3042.6 |
| Percentage of InterestIncomeOperating us-gaap:SeniorNotes | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 0.294 | 0.445 |
| Percentage of InterestExpenseDebt | 1.5 | 2.9 |
| Percentage of InterestIncomeOperating | 0.0 | 664.2 |
| Percentage of InterestIncomeOperating rily:BRileyPartnersOpportunityFund | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | -0.024 | 0.012 | 0.048 | 0.021 | 0.022 | 0.022 |
| Percentage of InterestExpenseDebt | -0.1 | 0.1 | 0.3 | 0.0 | 0.2 | 34.9 |
| Percentage of InterestIncomeOperating | 0.0 | 17.9 | 21.4 | 0.0 | 6.1 | 6.6 |
| Percentage of InterestIncomeOperating rily:ClearingOrganisation | 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 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 |
| Value | 0.067 | 0.224 | 0.246 | 0.248 | 0.361 | 0.331 | 0.637 | 0.59 | 0.442 | 0.166 | 0.128 | 16 | 0.076 | 0.15 | 0.132 | 0.286 | 0.026 | 0.003 | 0.003 | 0.007 | 0.005 | 0.003 | 0.0 | 0.089 | 0.331 |
| Percentage of InterestIncomeOperating | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Percentage of InterestIncomeOperating | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| 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 |
| Value | 23 | 29 | 24 | 21 | 22 | 21 | 14 | 17 | 14 | 13 | 12 | 9.008 | 7.327 | 8.623 | 1.504 | 1.386 | -0.129 |
| Percentage of InterestPaidNet | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 43726.9 | 10780.8 | 8855.7 | 9150.8 | 5907.8 | 4280.7 | 2737.0 | 2510.8 | 3036.4 | 7747.0 | 7037.5 | 44.0 | 11346.1 | 1002.7 | 1050.0 | -45.1 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 170 | 48 | 83 | -98.665 | 17 | 34 | 22 | 8.023 | -8.805 | 2.814 | 16 | 4.503 | -6.113 | 0.368 | 3.28 | 14 | 12 | 8.939 | -0.101 | 0.248 | -1.004 | 1.463 | 8.664 | 2.682 | -2.822 | -0.868 | -0.777 | -1.334 | 0.934 | 0.366 | -1.531 | 1.289 | 2.382 | -0.547 | 0.619 | 1.067 | -0.654 | 4.031 | -2.249 | -0.526 | -1.906 | 0.455 | -6.607 |
| Percentage of NetIncomeLoss | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 72207.5 | 37428.6 | -40107.7 | 6906.9 | 9501.9 | 6694.0 | 1259.5 | -1492.4 | 636.7 | 10239.2 | 3518.0 | -36.7 | 484.2 | 2186.7 | 10622.0 | 4349.7 | 34380.8 | -3366.7 | 8266.7 | -14342.9 | 29260.0 | 288800.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -614.6 | 187.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 | 0.251 | 0.513 | -1.311 | -0.584 | 0.387 | -0.158 | 0.152 | -0.044 | -0.16 | -0.092 | 0.804 | 0.339 | 0.662 | -0.246 | 0.083 | -0.12 | 10 | -0.565 | 0.074 | 1.122 | -0.042 | 1.155 | -0.095 | 0.754 | -0.08 | -0.048 | -0.13 | 0.264 | 0.066 | -0.13 | -0.064 | -0.354 | 0.194 | -0.22 | -0.845 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of NetIncomeLossAttributableToNoncontrollingInterest | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of InterestIncomeOperating | 0.0 | 765.7 | -585.3 | -237.4 | 156.0 | -43.8 | 45.9 | -6.9 | -27.1 | -20.8 | 484.3 | 264.8 | 4.0 | -323.7 | 55.3 | -90.9 | 3695.5 | -2173.1 | 2466.7 | 37400.0 | -600.0 | 23100.0 | -3166.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -247.2 | -255.3 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 0.251 | 0.513 | -1.311 | 0.387 | -0.158 | 0.152 |
| Percentage of NetIncomeLossAttributableToNoncontrollingInterest | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 765.7 | -585.3 | 156.0 | -43.8 | 45.9 |
| Percentage of InterestIncomeOperating us-gaap:CorporateAndOther | 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 |
| Value | 47 | 82 | -99.72 | 16 | 34 | 22 | 8.023 |
| Percentage of NetIncomeLossAvailableToCommonStockholdersBasic | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 70583.6 | 36943.3 | -40536.6 | 6800.4 | 9501.9 | 6694.0 | 1259.5 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 |
| Value | 47 | 82 | 34 | 22 |
| Percentage of NetIncomeLossAvailableToCommonStockholdersBasic | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 70583.6 | 36943.3 | 9501.9 | 6694.0 |
| Percentage of InterestIncomeOperating us-gaap:CorporateAndOther | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | 170 | 47 | 82 | -99.72 |
| Percentage of NetIncomeLossAvailableToCommonStockholdersDiluted | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 70583.6 | 36943.3 | -40536.6 |
| 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 |
| Value | 159 | 142 | 135 | 120 | 127 | 120 | 120 | 117 | 108 | 86 | 97 | 85 | 95 | 91 | 64 | 42 | 61 | 41 | 20 | 18 | 21 | 17 | 30 |
| Percentage of OperatingExpenses | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 213062.7 | 60325.0 | 49161.8 | 51479.8 | 33299.7 | 36383.4 | 18390.9 | 18400.8 | 19647.7 | 58447.6 | 66543.8 | 575.6 | 119828.9 | 42744.0 | 31959.1 | 21580.4 | 159784.6 | 669366.7 | 609366.7 | 301242.9 | 359900.0 | 1026400.0 |
| 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 | 2011-03-31 | 2010-12-31 | 2010-09-30 | 2010-06-30 |
| Value | 251 | 83 | 131 | -121.144 | 37 | 59 | 44 | 24 | -6.534 | 12 | 28 | 10 | 14 | 1.356 | 2.56 | 10 | 31 | 15 | 0.18 | 1.665 | -1.326 | 3.277 | 14 | 5.462 | -3.669 | -1.253 | -1.056 | -1.258 | 2.906 | 0.782 | -1.935 | 2.345 | 4.936 | -0.659 | 0.764 | 2.4 | 0.32 | 9.028 | -2.213 | 0.305 | -0.846 | 2.427 | -9.743 |
| 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 |
| Percentage of InterestIncomeOperating | 0.0 | 124628.4 | 58633.9 | -49245.5 | 15148.0 | 16579.2 | 13370.1 | 3921.2 | -1107.5 | 2904.5 | 17155.4 | 8282.8 | 85.3 | 1784.2 | 1706.7 | 8114.4 | 10999.3 | 59315.4 | 6000.0 | 55500.0 | -18942.9 | 65540.0 | 488966.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -740.4 | 230.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 | 2019-09-30 | 2019-03-31 | 2018-03-31 |
| Value | 7.46 | 12 | -60.818 | 5.953 | 11 | 8.051 |
| Percentage of OperatingIncomeLoss | 3.0 | 14.4 | -161.9 | 9.9 | 46.1 | 75.9 |
| Percentage of InterestIncomeOperating | 0.0 | 17910.4 | -24523.4 | 1649.0 | 1806.0 | 6289.8 |
| Percentage of InterestIncomeOperating rily:AuctionAndLiquidationSegment | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-03-31 |
| Value | 226 | 64 | 132 | 81 | 52 | 24 | 13 | -0.297 |
| Percentage of OperatingIncomeLoss | 90.4 | 77.6 | 100.9 | 215.7 | 87.6 | 55.1 | 55.5 | -2.8 |
| Percentage of InterestIncomeOperating | 0.0 | 96732.8 | 59182.6 | 32668.1 | 14515.8 | 7369.5 | 2176.0 | -232.0 |
| Percentage of InterestIncomeOperating rily:CapitalMarketsSegment | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 | 2019-09-30 |
| Value | 7.3 | 8.368 | 8.787 | 8.662 |
| Percentage of OperatingIncomeLoss | 2.9 | 10.0 | 23.4 | 14.5 |
| Percentage of InterestIncomeOperating | 0.0 | 12489.6 | 3543.1 | 2399.4 |
| Percentage of InterestIncomeOperating rily:PrincipalInvestmentsUnitedOnlineAndMagicJackSegment | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2019-09-30 | 2019-03-31 | 2018-03-31 |
| Value | 2.972 | 3.451 | 1.363 | 1.928 |
| Percentage of OperatingIncomeLoss | 3.6 | 5.8 | 5.5 | 18.2 |
| Percentage of InterestIncomeOperating | 4435.8 | 956.0 | 214.0 | 1506.2 |
| Percentage of InterestIncomeOperating rily:ValuationAndAppraisalSegment | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 | 1344000.0 | 526000.0 | 515000.0 | -1220000.0 | 357000.0 | -521000.0 | 167000.0 | 170000.0 | -465000.0 | -77000.0 | -865000.0 | -220000.0 | -213000.0 | 345000.0 | 401000.0 | 645000.0 | -614000.0 | -23000.0 | -82000.0 | 65000.0 | -123000.0 | -279000.0 | 71000.0 | -79000.0 | -21000.0 | 31000.0 | 4000.0 | -24000.0 | 171000.0 | -63000.0 | 129000.0 | -355000.0 | -484000.0 | -52000.0 | 52000.0 | 211000.0 | -160000.0 | 36000.0 | -110000.0 |
| Percentage of OtherComprehensiveIncomeLossNetOfTax | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 InterestIncomeOperating | 0.0 | 785.1 | 229.9 | -495.9 | 144.0 | -144.3 | 50.5 | 26.7 | -78.8 | -17.4 | -521.1 | -171.9 | -1.3 | 453.9 | 267.3 | 488.6 | -214.7 | -88.5 | -2733.3 | 2166.7 | -1757.1 | -5580.0 | 2366.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -58.4 | 15.7 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 |
| Value | 526000.0 | 515000.0 | -521000.0 | 167000.0 |
| Percentage of OtherComprehensiveIncomeLossNetOfTax | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 785.1 | 229.9 | -144.3 | 50.5 |
| Percentage of InterestIncomeOperating us-gaap:AccumulatedOtherComprehensiveIncome | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 | 171 | 48 | 82 | -99.249 | 17 | 34 | 22 | 7.979 | -8.965 | 2.722 | 17 | 4.842 | -5.451 | 0.122 | 3.363 | 13 | 23 | 8.374 | -0.027 | 1.37 | -1.046 | 2.618 | 8.569 | 3.436 | -2.902 | -0.916 | -0.907 | -1.07 | 1.0 | 0.236 | -1.595 | 0.935 | 2.576 | -0.767 | 1.464 | 1.067 | -0.654 | 4.031 | -2.249 | -0.526 |
| 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 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 InterestIncomeOperating | 0.0 | 72973.1 | 36843.3 | -40345.1 | 7062.9 | 9458.2 | 6739.9 | 1252.6 | -1519.5 | 615.8 | 10723.5 | 3782.8 | -32.7 | 160.5 | 2242.0 | 10531.1 | 8045.1 | 32207.7 | -900.0 | 45666.7 | -14942.9 | 52360.0 | 285633.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -861.8 | 442.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 171 | 48 | 82 | 17 | 34 | 22 |
| Percentage of ProfitLoss | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 72973.1 | 36843.3 | 7062.9 | 9458.2 | 6739.9 |
| Percentage of InterestIncomeOperating us-gaap:CorporateAndOther | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 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 |
| Value | 0.513 | -1.311 | -0.158 | 0.152 | -0.044 | -0.16 | -0.092 | 0.732 | 0.306 | -0.137 | -0.186 | 0.107 | -0.091 | -0.046 | 0.013 | 0.074 | 1.122 | -0.042 | 1.155 | -0.095 | 0.754 | -0.08 | -0.048 | -0.13 | 0.264 | 0.066 | -0.13 | -0.064 | -0.354 | 0.194 | -0.22 |
| Percentage of ProfitLoss | 1.0 | -1.6 | -0.5 | 0.7 | -0.6 | 1.8 | -3.4 | 4.1 | 6.3 | 2.5 | -152.5 | 3.2 | -0.7 | -0.2 | 0.2 | -274.1 | 81.9 | 4.0 | 44.1 | -1.1 | 21.9 | 2.8 | 5.2 | 14.3 | -24.7 | 6.6 | -55.1 | 4.0 | -37.9 | 7.5 | 28.7 |
| Percentage of InterestIncomeOperating | 765.7 | -585.3 | -43.8 | 45.9 | -6.9 | -27.1 | -20.8 | 441.0 | 239.1 | -0.8 | -244.7 | 71.3 | -68.9 | -16.1 | 50.0 | 2466.7 | 37400.0 | -600.0 | 23100.0 | -3166.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -247.2 |
| Percentage of InterestIncomeOperating us-gaap:NoncontrollingInterest | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 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 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 |
| Value | 48 | 83 | 34 | 22 | 8.023 | -8.805 | 2.814 | 16 | 4.503 | -6.113 | 0.368 | 3.28 | 14 | 12 | 8.939 | -0.101 | 0.248 | -1.004 | 1.463 | 8.664 | 2.682 | -2.822 | -0.868 | -0.777 | -1.334 | 0.934 | 0.366 | -1.531 | 1.289 | 2.382 | -0.547 | 0.619 | 1.067 | -0.654 | 4.031 |
| Percentage of ProfitLoss | 99.0 | 101.6 | 100.5 | 99.3 | 100.6 | 98.2 | 103.4 | 95.5 | 93.0 | 112.1 | 301.6 | 97.5 | 100.9 | 54.1 | 106.7 | 374.1 | 18.1 | 96.0 | 55.9 | 101.1 | 78.1 | 97.2 | 94.8 | 85.7 | 124.7 | 93.4 | 155.1 | 96.0 | 137.9 | 92.5 | 71.3 | 42.3 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 72207.5 | 37428.6 | 9501.9 | 6694.0 | 1259.5 | -1492.4 | 636.7 | 10239.2 | 3518.0 | -36.7 | 484.2 | 2186.7 | 10622.0 | 4349.7 | 34380.8 | -3366.7 | 8266.7 | -14342.9 | 29260.0 | 288800.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -614.6 | 187.0 | 0.0 | 0.0 | 0.0 |
| Percentage of InterestIncomeOperating 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 | 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 | 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 | 410 | 150 | 121 | -0.206 | 165 | 111 | 138 | 103 | 102 | 88 | 104 | 86 | 110 | 92 | 66 | 52 | 93 | 56 | 20 | 19 | 19 | 21 | 45 | 26 | 19 | 20 | 14 | 21 | 18 | 21 | 15 | 20 | 30 | 14 | 19 | 19 | 11 | 28 | 9.831 | 13 | 11 | 13 | 5.215 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 InterestIncomeOperating | 0.0 | 225320.9 | 54328.6 | -83.7 | 66627.8 | 30984.8 | 41969.2 | 16184.5 | 17293.4 | 20123.1 | 63063.9 | 67401.6 | 660.9 | 121613.2 | 44450.7 | 40073.5 | 32579.7 | 219100.0 | 675366.7 | 664866.7 | 282300.0 | 425440.0 | 1515366.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 15994.4 | 5936.9 | 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 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 11 | 30 | 7.396 | 11 | 4.492 | 5.883 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 2.7 | 20.1 | 6.1 | 7.0 | 4.0 | 4.2 |
| Percentage of InterestIncomeOperating | 0.0 | 45322.4 | 3301.8 | 4652.0 | 1244.3 | 1777.3 |
| Percentage of InterestIncomeOperating rily:AdvertisingLicensingAndOther | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 36 | 35 | 23 | 39 | 32 | 24 | 47 | 27 | 27 | 22 | 44 | 26 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 9.0 | 23.8 | 18.9 | -19143.7 | 19.6 | 21.5 | 34.3 | 26.3 | 26.5 | 25.1 | 42.3 | 30.8 |
| Percentage of InterestIncomeOperating | 0.0 | 53710.4 | 10289.7 | 16030.9 | 13076.6 | 6660.9 | 14375.8 | 4256.4 | 4584.6 | 5053.4 | 26663.9 | 20743.0 |
| Percentage of InterestIncomeOperating rily:CommissionsFeesAndReimbursedExpenses | 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 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 146 | 45 | 49 | 67 | 71 | 37 | 39 | 17 | 33 | 35 | 28 | 20 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 35.6 | 30.5 | 40.8 | -32709.7 | 43.4 | 33.8 | 28.5 | 17.3 | 32.4 | 40.4 | 26.8 | 24.3 |
| Percentage of InterestIncomeOperating | 0.0 | 68611.9 | 22166.5 | 27391.1 | 28907.7 | 10478.4 | 11962.8 | 2800.0 | 5601.9 | 8122.6 | 16903.0 | 16379.7 |
| Percentage of InterestIncomeOperating rily:CorporateFinanceAndInvestmentBankingFees | 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 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | -0.222 | 4.195 | 4.61 | 4.483 | -57.984 | 7.081 | 6.274 | 13 | 7.088 | 0.108 | 2.357 | 8.175 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | -0.1 | 2.8 | 3.8 | -2176.2 | -35.1 | 6.3 | 4.5 | 12.7 | 6.9 | 0.1 | 2.3 | 9.5 |
| Percentage of InterestIncomeOperating | 0.0 | 6261.2 | 2058.0 | 1822.4 | -23380.6 | 1961.5 | 1895.5 | 2052.7 | 1201.4 | 24.4 | 1419.9 | 6386.7 |
| Percentage of InterestIncomeOperating rily:ServiceContractRevenues | 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 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 17 | 17 | 18 | 18 | 19 | 19 | 21 | 22 | 15 | 9.151 | 9.044 | 9.141 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 4.3 | 11.9 | 15.0 | -9142.2 | 11.6 | 17.4 | 15.2 | 21.7 | 15.2 | 10.3 | 8.6 | 10.6 |
| Percentage of InterestIncomeOperating | 0.0 | 26788.1 | 8163.8 | 7655.7 | 7739.5 | 5380.9 | 6365.9 | 3516.2 | 2635.9 | 2070.4 | 5448.2 | 7141.4 |
| Percentage of InterestIncomeOperating rily:SubscriptionServices | 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 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 23 | 16 | 18 | 20 | 27 | 18 | 18 | 17 | 17 | 19 | 18 | 19 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 5.6 | 10.9 | 15.4 | -9864.1 | 16.8 | 17.0 | 13.3 | 17.0 | 17.2 | 21.6 | 17.8 | 22.2 |
| Percentage of InterestIncomeOperating | 0.0 | 24626.9 | 8348.7 | 8260.2 | 11189.5 | 5258.7 | 5591.8 | 2752.7 | 2980.0 | 4337.3 | 11197.0 | 14976.6 |
| Percentage of InterestIncomeOperating rily:WealthAndAssetManagementFees | 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 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 1.906 | 22 | 1.045 | 2.99 | 0.054 | 1.176 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 0.5 | 15.0 | 0.9 | 1.8 | 0.0 | 0.8 |
| Percentage of InterestIncomeOperating | 0.0 | 33898.5 | 466.5 | 1205.6 | 15.0 | 355.3 |
| Percentage of InterestIncomeOperating rily:AdvertisingLicensingAndOther rily:AuctionAndLiquidation | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 |
| Value | 5.451 | 4.0 | 3.206 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 1.3 | 2.6 | 2.6 |
| Percentage of InterestIncomeOperating | 0.0 | 5970.1 | 1431.2 |
| Percentage of InterestIncomeOperating rily:AdvertisingLicensingAndOther rily:Brands | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 3.784 | 3.654 | 3.145 | 4.492 | 4.438 | 4.707 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 0.9 | 2.4 | 2.6 | 2.7 | 4.0 | 3.4 |
| Percentage of InterestIncomeOperating | 0.0 | 5453.7 | 1404.0 | 1811.3 | 1229.4 | 1422.1 |
| Percentage of InterestIncomeOperating rily:AdvertisingLicensingAndOther rily:PrincipalInvestmentsUnitedOnlineAndMagicJack | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 13 | 17 | 2.596 | 10 | 4.151 | 27 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 3.4 | 11.4 | 2.1 | 6.4 | 3.7 | 19.8 |
| Percentage of InterestIncomeOperating | 0.0 | 25788.1 | 1158.9 | 4273.8 | 1149.9 | 8297.9 |
| Percentage of InterestIncomeOperating rily:CommissionsFeesAndReimbursedExpenses rily:AuctionAndLiquidation | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 12 | 9.053 | 12 | 12 | 9.077 | 10 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 3.0 | 6.0 | 10.5 | 7.4 | 8.1 | 7.5 |
| Percentage of InterestIncomeOperating | 0.0 | 13511.9 | 5707.6 | 4900.4 | 2514.4 | 3134.7 |
| Percentage of InterestIncomeOperating rily:CommissionsFeesAndReimbursedExpenses rily:CapitalMarkets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 |
| Value | 9.655 | 7.668 | 10 | 9.742 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 6.4 | 6.3 | 9.7 | 7.0 |
| Percentage of InterestIncomeOperating | 14410.4 | 3423.2 | 2996.7 | 2943.2 |
| Percentage of InterestIncomeOperating rily:CommissionsFeesAndReimbursedExpenses rily:ValuationAndAppraisal | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 92 | 45 | 49 | 34 | 37 | 39 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 22.4 | 30.5 | 40.8 | 20.7 | 33.8 | 28.5 |
| Percentage of InterestIncomeOperating | 0.0 | 68611.9 | 22166.5 | 13798.4 | 10478.4 | 11962.8 |
| Percentage of InterestIncomeOperating rily:CorporateFinanceAndInvestmentBankingFees rily:CapitalMarkets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | -0.222 | 4.195 | 4.61 | -57.984 | 7.081 | 6.274 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | -0.1 | 2.8 | 3.8 | -35.1 | 6.3 | 4.5 |
| Percentage of InterestIncomeOperating | 0.0 | 6261.2 | 2058.0 | -23380.6 | 1961.5 | 1895.5 |
| Percentage of InterestIncomeOperating rily:ServiceContractRevenues rily:AuctionAndLiquidation | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 17 | 17 | 18 | 19 | 19 | 21 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 4.3 | 11.9 | 15.0 | 11.6 | 17.4 | 15.2 |
| Percentage of InterestIncomeOperating | 0.0 | 26788.1 | 8163.8 | 7739.5 | 5380.9 | 6365.9 |
| Percentage of InterestIncomeOperating rily:SubscriptionServices rily:PrincipalInvestmentsUnitedOnlineAndMagicJack | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 23 | 16 | 18 | 27 | 18 | 18 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 5.6 | 10.9 | 15.4 | 16.8 | 17.0 | 13.3 |
| Percentage of InterestIncomeOperating | 0.0 | 24626.9 | 8348.7 | 11189.5 | 5258.7 | 5591.8 |
| Percentage of InterestIncomeOperating rily:WealthAndAssetManagementFees rily:CapitalMarkets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 15 | 44 | 8.251 | -44.395 | 11 | 34 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 3.8 | 29.3 | 6.8 | -26.9 | 10.1 | 25.1 |
| Percentage of InterestIncomeOperating | 0.0 | 65947.8 | 3683.5 | -17901.2 | 3126.3 | 10548.6 |
| Percentage of InterestIncomeOperating rily:AuctionAndLiquidation | 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 |
| Value | 5.451 | 4.0 | 3.206 | 3.801 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 1.3 | 2.6 | 2.6 | -1845.1 |
| Percentage of InterestIncomeOperating | 0.0 | 5970.1 | 1431.2 | 1545.1 |
| Percentage of InterestIncomeOperating rily:Brands | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 127 | 71 | 81 | 74 | 65 | 68 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 31.0 | 47.4 | 66.7 | 44.9 | 58.9 | 49.3 |
| Percentage of InterestIncomeOperating | 0.0 | 106750.7 | 36222.8 | 29888.3 | 18251.5 | 20689.4 |
| Percentage of InterestIncomeOperating rily:CapitalMarkets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 21 | 21 | 21 | 23 | 23 | 25 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 5.2 | 14.3 | 17.6 | 14.3 | 21.3 | 18.6 |
| Percentage of InterestIncomeOperating | 0.0 | 32241.8 | 9567.9 | 9550.8 | 6610.2 | 7787.9 |
| Percentage of InterestIncomeOperating rily:PrincipalInvestmentsUnitedOnlineAndMagicJack | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 |
| Value | 9.655 | 7.668 | 10 | 9.742 |
| Percentage of RevenueFromContractWithCustomerExcludingAssessedTax | 6.4 | 6.3 | 9.7 | 7.0 |
| Percentage of InterestIncomeOperating | 14410.4 | 3423.2 | 2996.7 | 2943.2 |
| Percentage of InterestIncomeOperating rily:ValuationAndAppraisal | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 | 410 | 150 | 121 | -0.206 | 165 | 111 | 138 | 142 | 102 | 99 | 125 | 95 | 110 | 92 | 66 | 52 | 93 | 56 | 20 | 19 | 19 | 21 | 45 | 26 | 19 | 20 | 14 | 21 | 18 | 21 | 15 | 20 | 30 | 14 | 19 | 19 | 11 | 28 | 9.831 | 13 | 11 | 13 | 5.215 |
| 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 |
| Percentage of InterestIncomeOperating | 0.0 | 225320.9 | 54328.6 | -83.7 | 66627.8 | 30984.8 | 41969.2 | 22312.1 | 17293.4 | 22552.3 | 75603.0 | 74826.6 | 660.9 | 121613.2 | 44450.7 | 40073.5 | 32579.7 | 219100.0 | 675366.7 | 664866.7 | 282300.0 | 425440.0 | 1515366.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 15994.4 | 5936.9 | 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 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 15 | 44 | 8.251 | -44.395 | 11 | 34 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 3.8 | 29.3 | 6.8 | -26.9 | 10.1 | 25.1 |
| Percentage of InterestIncomeOperating | 0.0 | 65947.8 | 3683.5 | -17901.2 | 3126.3 | 10548.6 |
| Percentage of InterestIncomeOperating rily:AuctionAndLiquidationSegment | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-03-31 |
| Value | 302 | 146 | 225 | 134 | 134 | 94 | 85 | 60 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 73.7 | 97.2 | 185.6 | 81.5 | 119.9 | 67.8 | 60.0 | 63.0 |
| Percentage of InterestIncomeOperating | 0.0 | 219120.9 | 100853.1 | 54331.5 | 37145.7 | 28473.7 | 13391.1 | 47132.0 |
| Percentage of InterestIncomeOperating rily:CapitalMarketsSegment | 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 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 21 | 21 | 21 | 23 | 23 | 25 |
| Percentage of RevenueFromContractWithCustomerIncludingAssessedTax | 5.2 | 14.3 | 17.6 | 14.3 | 21.3 | 18.6 |
| Percentage of InterestIncomeOperating | 0.0 | 32241.8 | 9567.4 | 9550.8 | 6610.2 | 7787.9 |
| Percentage of InterestIncomeOperating rily:PrincipalInvestmentsUnitedOnlineAndMagicJackSegment | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 | 410 | 226 | 266 | -0.206 | 165 | 180 | 164 | 142 | 102 | 99 | 125 | 95 | 110 | 92 | 66 | 52 | 93 | 56 | 20 | 19 | 19 | 21 | 45 | 26 | 19 | 20 | 14 | 21 | 18 | 21 | 15 | 20 | 30 | 14 | 19 | 19 | 11 | 28 | 9.831 | 13 | 11 | 13 | 5.215 |
| Percentage of Revenues | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 InterestIncomeOperating | 0.0 | 337691.0 | 118958.9 | -83.7 | 66627.8 | 49878.9 | 49753.5 | 22312.1 | 17293.4 | 22552.3 | 75603.0 | 74826.6 | 660.9 | 121613.2 | 44450.7 | 40073.5 | 32579.7 | 219100.0 | 675366.7 | 664866.7 | 282300.0 | 425440.0 | 1515366.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 15994.4 | 5936.9 | 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 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | -0.198 | 0.14 | -4.049 | -1.085 | 7.704 | 5.688 |
| Percentage of Revenues | -0.0 | 0.1 | -1.5 | -0.7 | 4.3 | 3.5 |
| Percentage of InterestIncomeOperating | 0.0 | 209.0 | -1807.6 | -437.5 | 2134.1 | 1718.4 |
| Percentage of InterestIncomeOperating rily:FairValueAdjustmentOnLoans | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 |
| Value | 30 | 26 | 24 | 21 | 23 | 25 | 7.665 | 9.33 | 8.962 | 8.954 | 6.591 | 7.291 | 10 | 6.897 | 2.218 |
| Percentage of Revenues | 7.3 | 11.5 | 9.2 | -10607.3 | 14.0 | 14.3 | 4.7 | 6.6 | 8.8 | 9.0 | 5.3 | 7.6 | 9.7 | 7.5 | 3.3 |
| Percentage of InterestIncomeOperating | 0.0 | 38844.8 | 10940.2 | 8882.5 | 9304.0 | 7137.4 | 2315.7 | 1464.7 | 1519.0 | 2025.8 | 3970.5 | 5696.1 | 63.8 | 9075.0 | 1478.7 |
| Percentage of InterestIncomeOperating rily:InterestIncomeSecuritiesLending | 0.0 | 0.0 | 0.0 | 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 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 5.435 | 17 | 5.719 | 2.812 | 2.174 | 3.21 |
| Percentage of Revenues | 1.3 | 7.7 | 2.1 | 1.7 | 1.2 | 1.9 |
| Percentage of InterestIncomeOperating | 0.0 | 26132.8 | 2553.1 | 1133.9 | 602.2 | 969.8 |
| Percentage of InterestIncomeOperating rily:Other | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 140 | 31 | 118 | 35 | 32 | -0.093 |
| Percentage of Revenues | 34.2 | 14.0 | 44.5 | 21.7 | 18.1 | -0.1 |
| Percentage of InterestIncomeOperating | 0.0 | 47183.6 | 52944.6 | 14442.7 | 9020.5 | -28.1 |
| Percentage of InterestIncomeOperating rily:TradingGainslossesOnInvestments | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | -0.198 | 0.14 | -4.049 | -1.085 | 7.704 | 5.688 |
| Percentage of Revenues | -0.0 | 0.1 | -1.5 | -0.7 | 4.3 | 3.5 |
| Percentage of InterestIncomeOperating | 0.0 | 209.0 | -1807.6 | -437.5 | 2134.1 | 1718.4 |
| Percentage of InterestIncomeOperating rily:FairValueAdjustmentOnLoans rily:CapitalMarkets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 30 | 26 | 24 | 23 | 25 | 16 |
| Percentage of Revenues | 7.3 | 11.5 | 9.2 | 14.0 | 14.3 | 10.3 |
| Percentage of InterestIncomeOperating | 0.0 | 38844.8 | 10940.2 | 9304.0 | 7137.4 | 5124.2 |
| Percentage of InterestIncomeOperating rily:InterestIncomeSecuritiesLending rily:CapitalMarkets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 4.719 | 17 | 5.719 | 2.812 | 2.174 | 3.21 |
| Percentage of Revenues | 1.2 | 7.7 | 2.1 | 1.7 | 1.2 | 1.9 |
| Percentage of InterestIncomeOperating | 0.0 | 26132.8 | 2553.1 | 1133.9 | 602.2 | 969.8 |
| Percentage of InterestIncomeOperating rily:Other rily:CapitalMarkets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 140 | 31 | 118 | 35 | 32 | -0.093 |
| Percentage of Revenues | 34.2 | 14.0 | 44.5 | 21.7 | 18.1 | -0.1 |
| Percentage of InterestIncomeOperating | 0.0 | 47183.6 | 52944.6 | 14442.7 | 9020.5 | -28.1 |
| Percentage of InterestIncomeOperating rily:TradingGainslossesOnInvestments rily:CapitalMarkets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 15 | 44 | 8.251 | -44.395 | 11 | 34 |
| Percentage of Revenues | 3.8 | 19.5 | 3.1 | -26.9 | 6.3 | 21.2 |
| Percentage of InterestIncomeOperating | 0.0 | 65947.8 | 3683.5 | -17901.2 | 3126.3 | 10548.6 |
| Percentage of InterestIncomeOperating rily:AuctionAndLiquidation | 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 |
| Value | 5.451 | 4.0 | 3.206 | 3.801 |
| Percentage of Revenues | 1.3 | 1.8 | 1.2 | -1845.1 |
| Percentage of InterestIncomeOperating | 0.0 | 5970.1 | 1431.2 | 1545.1 |
| Percentage of InterestIncomeOperating rily:Brands | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 302 | 146 | 225 | 134 | 134 | 94 |
| Percentage of Revenues | 73.7 | 64.9 | 84.8 | 81.5 | 74.5 | 57.2 |
| Percentage of InterestIncomeOperating | 0.0 | 219120.9 | 100853.1 | 54331.5 | 37145.7 | 28473.7 |
| Percentage of InterestIncomeOperating rily:CapitalMarkets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 21 | 21 | 21 | 23 | 23 | 25 |
| Percentage of Revenues | 5.2 | 9.5 | 8.0 | 14.3 | 13.3 | 15.7 |
| Percentage of InterestIncomeOperating | 0.0 | 32241.8 | 9567.9 | 9550.8 | 6610.2 | 7787.9 |
| Percentage of InterestIncomeOperating rily:PrincipalInvestmentsUnitedOnlineAndMagicJack | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 |
| Value | 9.655 | 7.668 | 10 | 9.742 |
| Percentage of Revenues | 4.3 | 2.9 | 6.0 | 5.9 |
| Percentage of InterestIncomeOperating | 14410.4 | 3423.2 | 2996.7 | 2943.2 |
| Percentage of InterestIncomeOperating rily:ValuationAndAppraisal | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-09-30 |
| Value | 6.094 | 1.038 | 0.0 |
| Percentage of Revenues | 2.7 | 0.4 | 0.0 |
| Percentage of InterestIncomeOperating | 9095.5 | 463.4 | 0.0 |
| Percentage of InterestIncomeOperating pf0:AU | 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 | 2017-06-30 |
| Value | 35 | 0.518 | 0.251 | 0.0 | 0.0 | 0.0 | 0.061 | 0.061 | 0.006 | 0.808 | 0.454 | 1.106 | 0.013 | -0.014 |
| Percentage of Revenues | 15.5 | 0.2 | -121.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 0.0 | 0.6 | 0.5 | 1.0 | 0.0 | -0.0 |
| Percentage of InterestIncomeOperating | 52286.6 | 231.2 | 102.0 | 0.0 | 0.0 | 0.0 | 9.6 | 10.3 | 1.4 | 486.7 | 354.7 | 6.6 | 17.1 | -9.3 |
| Percentage of InterestIncomeOperating srt:Europe | 0.0 | 0.0 | 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 | 2017-06-30 |
| Value | 185 | 264 | -1.121 | 165 | 180 | 164 | 142 | 101 | 99 | 124 | 95 | 94 | 92 | 66 |
| Percentage of Revenues | 81.8 | 99.4 | 544.2 | 100.0 | 100.0 | 100.0 | 99.9 | 99.9 | 100.0 | 99.4 | 99.5 | 85.9 | 100.0 | 99.9 |
| Percentage of InterestIncomeOperating | 276309.0 | 118264.3 | -455.7 | 66610.5 | 49878.9 | 49753.5 | 22300.2 | 17279.8 | 22550.9 | 75116.3 | 74471.9 | 568.1 | 121596.1 | 44394.0 |
| Percentage of InterestIncomeOperating srt:NorthAmerica | 0.0 | 0.0 | 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 | 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 | 137 | 97 | 106 | 87 | 110 | 96 | 87 | 90 | 77 | 71 | 76 | 68 | 80 | 70 | 37 | 24 | 33 | 22 | 14 | 11 | 12 | 12 | 20 | 12 | 13 | 12 | 10 | 7.984 | 8.334 | 7.085 | 10 | 10 | 13 | 7.878 | 9.758 | 8.519 | 6.098 | 10 | 8.16 | 7.791 | 6.796 | 8.018 | 8.083 |
| 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 |
| Percentage of InterestIncomeOperating | 0.0 | 144989.6 | 47572.3 | 35668.3 | 44657.7 | 26755.4 | 26386.1 | 14214.0 | 13064.2 | 16240.3 | 46218.7 | 53201.6 | 480.9 | 93371.1 | 25148.0 | 18297.0 | 11637.4 | 87411.5 | 484033.3 | 386533.3 | 179528.6 | 255640.0 | 669066.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 8851.7 | 2948.0 | 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 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-03-31 |
| Value | 3.477 | 4.625 | 2.729 | 1.686 | 2.835 | 3.295 | 2.915 | 2.881 |
| Percentage of SellingGeneralAndAdministrativeExpense | 2.5 | 4.8 | 2.6 | 1.5 | 2.9 | 3.8 | 3.2 | 4.2 |
| Percentage of InterestIncomeOperating | 0.0 | 6903.0 | 1218.3 | 679.8 | 785.3 | 995.5 | 457.6 | 2250.8 |
| Percentage of InterestIncomeOperating rily:AuctionAndLiquidationSegment | 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 |
| Value | 0.682 | 0.994 | 0.309 | 0.904 |
| Percentage of SellingGeneralAndAdministrativeExpense | 0.5 | 1.0 | 0.3 | 1.0 |
| Percentage of InterestIncomeOperating | 0.0 | 1483.6 | 137.9 | 367.5 |
| Percentage of InterestIncomeOperating rily:BrandsSegment | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-03-31 |
| Value | 63 | 68 | 81 | 43 | 70 | 63 | 63 | 53 |
| Percentage of SellingGeneralAndAdministrativeExpense | 46.1 | 70.5 | 76.0 | 39.0 | 72.6 | 72.2 | 70.0 | 78.8 |
| Percentage of InterestIncomeOperating | 0.0 | 102152.2 | 36174.1 | 17397.6 | 19429.4 | 19045.6 | 9951.2 | 41905.5 |
| Percentage of InterestIncomeOperating rily:CapitalMarketsSegment | 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 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 6.0 | 4.84 | 4.049 | 5.846 | 5.895 | 5.495 |
| Percentage of SellingGeneralAndAdministrativeExpense | 4.4 | 5.0 | 3.8 | 5.3 | 6.1 | 6.3 |
| Percentage of InterestIncomeOperating | 0.0 | 7223.9 | 1807.6 | 2357.3 | 1633.0 | 1660.1 |
| Percentage of InterestIncomeOperating rily:PrincipalInvestmentsUnitedOnlineAndMagicJackSegment | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-03-31 |
| Value | 6.632 | 6.144 | 7.331 | 6.974 | 2.766 | 2.345 |
| Percentage of SellingGeneralAndAdministrativeExpense | 6.8 | 5.8 | 7.6 | 8.0 | 3.1 | 3.4 |
| Percentage of InterestIncomeOperating | 9898.5 | 2742.9 | 2030.7 | 2106.9 | 434.2 | 1832.0 |
| Percentage of InterestIncomeOperating rily:ValuationAndAppraisalSegment | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 | 2662 | 2300 | 2295 | 2130 | 2318 | 2106 | 1978 | 1917 | 1957 | 1920 | 1877 | 1430 | 1386 | 1226 | 1341 | 254 | 264 | 261 | 169 | 126 | 132 | 142 | 147 | 135 | 138 | 115 | 120 | 62 | 73 | 65 | 67 | 77 | 80 | 72 | 74 | 78 | 76 | 91 | 68 | 72 |
| 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 |
| 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 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 2123 | 1900 | 1959 | 1867 | 1927 | 1807 | 1701 | 1654 | 1699 | 1651 | 1612 | 1158 | 1121 | 951 | 1101 | 92 | 114 | 117 | 35 | 14 | 23 | 29 | 34 | 30 | 41 | 26 | 30 | 68 | 77 | 70 | 72 | 81 | 84 | 79 | 80 | 85 | 84 | 99 | 79 | 81 |
| 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 |
| Percentage of Assets | 79.8 | 82.6 | 85.4 | 87.7 | 83.2 | 85.8 | 86.0 | 86.2 | 86.8 | 86.0 | 85.9 | 81.0 | 80.8 | 77.6 | 82.1 | 36.5 | 43.2 | 45.1 | 20.7 | 11.9 | 17.4 | 20.6 | 23.2 | 22.7 | 30.2 | 22.8 | 25.3 | 108.3 | 105.6 | 108.1 | 107.5 | 104.7 | 105.2 | 108.6 | 107.3 | 108.9 | 110.8 | 108.1 | 116.9 | 112.3 |
| 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 | 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 | 2662 | 2300 | 2295 | 2130 | 2318 | 2106 | 1978 | 1917 | 1957 | 1920 | 1877 | 1430 | 1386 | 1226 | 1341 | 254 | 264 | 261 | 169 | 126 | 132 | 142 | 147 | 135 | 138 | 115 | 120 | 62 | 73 | 65 | 67 | 77 | 80 | 72 | 74 | 78 | 76 | 91 | 68 | 72 |
| 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 |
| 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 |
| 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 | 2011-03-31 | 2010-12-31 | 2009-12-31 | 2008-12-31 |
| Value | 512 | 373 | 310 | 235 | 360 | 298 | 276 | 263 | 258 | 268 | 263 | 271 | 266 | 274 | 239 | 161 | 149 | 142 | 133 | 110 | 109 | 111 | 112 | 104 | 97 | 89 | 90 | -5.52 | -4.163 | -5.268 | -5.571 | -4.169 | -5.103 | -7.001 | -6.402 | -6.978 | -8.256 | -7.442 | -11.495 | -9.181 | -8.903 | -1.0 | 14 |
| 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 | 19.3 | 16.3 | 13.5 | 11.0 | 15.6 | 14.2 | 14.0 | 13.7 | 13.2 | 14.0 | 14.0 | 19.0 | 19.2 | 22.4 | 17.8 | 63.2 | 56.4 | 54.5 | 78.6 | 87.3 | 82.6 | 78.1 | 76.3 | 76.8 | 69.8 | 77.1 | 74.5 | -8.8 | -5.7 | -8.0 | -8.2 | -5.4 | -6.3 | -9.6 | -8.5 | -8.9 | -10.8 | -8.1 | -16.9 | 0.0 | -12.3 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 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 | 103 | 169 | 106 | 124 | 104 | 170 | 55 | 163 | 179 | 233 | 191 | 74 | 132 | 102 | 104 | 71 | 112 | 26 | 48 | 26 | 30 | 45 | 42 | 10 | 21 | 25 | 43 | 16 | 18 | 13 | 20 | 31 | 18 | 18 | 23 | 20 | 15 | 16 | 17 | 21 | 20 | 21 | 26 | 37 | 16 |
| 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 |
| Percentage of Assets | 3.9 | 7.4 | 4.6 | 5.8 | 4.5 | 8.1 | 2.8 | 8.5 | 9.2 | 12.2 | 10.2 | 5.2 | 9.6 | 8.4 | 7.8 | 28.1 | 42.4 | 10.1 | 28.4 | 21.2 | 22.7 | 32.3 | 28.6 | 7.6 | 15.5 | 22.1 | 35.6 | 26.9 | 25.6 | 21.3 | 30.4 | 40.1 | 23.2 | 26.1 | 31.2 | 26.4 | 19.7 | 17.9 | 25.5 | 0.0 | 27.8 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2016-12-31 | 2015-12-31 |
| Value | 104 | 171 | 106 | 124 | 104 | 171 | 58 | 170 | 180 | 234 | 191 | 97 | 152 | 111 | 110 | 115 | 30 |
| Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 3.9 | 7.4 | 4.6 | 5.9 | 4.5 | 8.1 | 2.9 | 8.9 | 9.2 | 12.2 | 10.2 | 6.8 | 11.0 | 9.1 | 8.2 | 43.6 | 22.7 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 46 | 45 | 43 | 46 | 46 | 47 | 56 | 43 | 42 | 38 | 33 | 25 | 20 | 19 | 19 | 18 | 18 | 15 | 7.997 | 7.945 | 9.472 | 10 | 23 | 14 | 10 | 11 | 14 | 10 | 8.858 | 9.675 | 9.015 | 9.05 | 16 | 6.148 | 5.816 | 8.179 | 7.482 | 12 | 4.884 | 3.087 |
| 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 |
| Percentage of Assets | 1.7 | 2.0 | 1.9 | 2.2 | 2.0 | 2.3 | 2.9 | 2.3 | 2.2 | 2.0 | 1.8 | 1.8 | 1.4 | 1.6 | 1.4 | 7.1 | 7.2 | 5.8 | 4.7 | 6.3 | 7.2 | 7.1 | 15.9 | 10.9 | 7.3 | 10.0 | 11.6 | 16.1 | 12.0 | 14.8 | 13.3 | 11.7 | 20.6 | 8.4 | 7.8 | 10.4 | 9.8 | 13.5 | 7.2 | 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 | 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 | 87 | 87 | 105 | 114 | 81 | 112 | 140 | 87 | 79 | 50 | 42 | 39 | 22 | 20 | 10 | 3.592 | 3.578 | 4.543 | 8.507 | 2.993 | 2.415 | 1.351 | 1.229 | 1.2 | 3.795 | 1.453 | 1.578 | 1.516 | 0.948 | 1.237 | 1.572 | 1.608 | 1.145 | 1.175 | 0.961 | 1.482 | 1.11 | 2.785 | 2.039 | 1.353 |
| 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 |
| Percentage of Assets | 3.3 | 3.8 | 4.6 | 5.4 | 3.5 | 5.3 | 7.1 | 4.6 | 4.1 | 2.6 | 2.2 | 2.8 | 1.6 | 1.7 | 0.8 | 1.4 | 1.4 | 1.7 | 5.0 | 2.4 | 1.8 | 0.9 | 0.8 | 0.9 | 2.7 | 1.3 | 1.3 | 2.4 | 1.3 | 1.9 | 2.3 | 2.1 | 1.4 | 1.6 | 1.3 | 1.9 | 1.5 | 3.0 | 3.0 | 1.9 |
| 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 | 2017-12-31 |
| Value | 11 | 12 | 12 | 12 | 13 | 13 | 15 | 15 | 11 | 11 | 11 |
| 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 |
| Percentage of Assets | 0.5 | 0.5 | 0.6 | 0.5 | 0.6 | 0.7 | 0.8 | 0.8 | 0.6 | 0.6 | 0.9 |
| 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 | 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 | 30 | 31 | 35 | 19 | 10 | 4.259 | 4.063 | 4.039 | 3.691 | 3.055 |
| Percentage of PropertyPlantAndEquipmentGross | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 1.1 | 1.3 | 1.8 | 1.4 | 4.1 | 3.2 | 2.9 | 5.5 | 4.6 | 4.0 |
| 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 | 15 | 14 | 18 | 9.474 | 6.559 | 2.4 | 2.28 | 2.179 |
| Percentage of PropertyPlantAndEquipmentGross | 51.3 | 47.6 | 52.8 | 47.4 | 60.7 | 56.4 | 56.1 | 53.9 |
| Percentage of Assets | 0.6 | 0.6 | 1.0 | 0.7 | 2.5 | 1.8 | 1.6 | 3.0 |
| Percentage of Assets rily:MachineryEquipmentAndComputerSoftware | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 4.128 | 4.305 | 5.143 | 2.688 | 1.921 | 1.16 | 1.151 | 1.176 | 0.974 | 0.863 |
| Percentage of PropertyPlantAndEquipmentGross | 13.5 | 13.8 | 14.6 | 13.4 | 17.8 | 27.2 | 28.3 | 29.1 | 26.4 | 28.2 |
| Percentage of Assets | 0.2 | 0.2 | 0.3 | 0.2 | 0.7 | 0.9 | 0.8 | 1.6 | 1.2 | 1.1 |
| Percentage of Assets us-gaap:FurnitureAndFixtures | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 10 | 12 | 11 | 7.834 | 2.325 | 0.311 | 0.244 | 0.296 | 0.282 | 0.148 |
| Percentage of PropertyPlantAndEquipmentGross | 35.2 | 38.6 | 32.6 | 39.2 | 21.5 | 7.3 | 6.0 | 7.3 | 7.6 | 4.8 |
| Percentage of Assets | 0.4 | 0.5 | 0.6 | 0.6 | 0.9 | 0.2 | 0.2 | 0.4 | 0.3 | 0.2 |
| Percentage of Assets us-gaap:LeaseholdImprovements | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 | 2015-12-31 | 2014-12-31 | 2013-12-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 |
| Value | 18 | 18 | 19 | 8.019 | 5.02 | 3.667 | 3.287 | 2.949 | 2.721 | 0.095 | 0.048 | 0.219 |
| 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 | 100.0 |
| Percentage of Assets | 0.7 | 0.8 | 1.0 | 0.6 | 1.9 | 2.8 | 2.4 | 4.0 | 3.4 | 0.1 | 0.1 | 0.3 |
| 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 | 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 | 11 | 11 | 12 | 12 | 12 | 13 | 13 | 15 | 15 | 11 | 11 | 11 | 11 | 13 | 13 | 5.409 | 5.785 | 5.765 | 0.475 | 0.519 | 0.592 | 0.651 | 0.729 | 0.803 | 0.776 | 0.862 | 0.956 | 0.995 | 1.09 | 1.066 | 1.335 | 1.036 | 0.97 | 0.897 | 0.96 | 0.827 | 0.916 | 1.059 | 1.241 | 1.369 |
| Percentage of PropertyPlantAndEquipmentNet | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 0.4 | 0.5 | 0.5 | 0.6 | 0.5 | 0.6 | 0.7 | 0.8 | 0.8 | 0.6 | 0.6 | 0.8 | 0.9 | 1.1 | 1.0 | 2.1 | 2.2 | 2.2 | 0.3 | 0.4 | 0.4 | 0.5 | 0.5 | 0.6 | 0.6 | 0.7 | 0.8 | 1.6 | 1.5 | 1.6 | 2.0 | 1.3 | 1.2 | 1.2 | 1.3 | 1.0 | 1.2 | 1.2 | 1.8 | 1.9 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 11 | 12 |
| Percentage of PropertyPlantAndEquipmentNet | 100.0 | 100.0 |
| Percentage of Assets | 0.4 | 0.5 |
| Percentage of Assets srt:NorthAmerica | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2015-02-02 | 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 | 227 | 227 | 227 | 223 | 223 | 220 | 220 | 223 | 223 | 120 | 99 | 98 | 98 | 100 | 67 | 48 | 48 | 52 | 34 | 34 | 34 | 34 | 34 | 34 | 6.971 | 27 | 27 | 27 | 5.688 | 5.688 | 5.688 | 5.688 | 5.688 | 5.688 | 5.688 | 5.688 | 5.688 | 5.688 | 5.688 | 5.688 | 5.688 |
| Percentage of Goodwill | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 8.5 | 9.9 | 9.9 | 10.5 | 9.6 | 10.5 | 11.1 | 11.6 | 11.4 | 6.3 | 5.3 | 6.9 | 7.1 | 8.2 | 5.0 | 19.2 | 18.5 | 20.1 | 20.4 | 27.4 | 26.1 | 24.3 | 23.4 | 25.4 | 0.0 | 19.8 | 23.9 | 23.0 | 9.0 | 7.7 | 8.7 | 8.4 | 7.3 | 7.1 | 7.8 | 7.6 | 7.2 | 7.4 | 6.2 | 8.4 | 7.9 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2014-12-31 |
| Value | 79 | 79 | 79 | 21 |
| Percentage of Goodwill | 34.9 | 35.4 | 35.5 | 79.4 |
| Percentage of Assets | 3.0 | 3.4 | 4.0 | 15.7 |
| Percentage of Assets rily:CapitalMarketsSegment | 0.0 | 0.0 | 0.0 | 44.7 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 |
| Value | 23 | 20 | 20 |
| Percentage of Goodwill | 10.4 | 9.1 | 9.1 |
| Percentage of Assets | 0.9 | 0.9 | 1.0 |
| Percentage of Assets rily:FinancialConsultingSegment | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 |
| Value | 122 | 122 | 121 |
| Percentage of Goodwill | 53.8 | 54.6 | 54.6 |
| Percentage of Assets | 4.6 | 5.3 | 6.2 |
| Percentage of Assets rily:PrincipalInvestmentsUnitedOnlineAndMagicJackSegment | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 | 190 | 194 | 199 | 212 | 220 | 79 | 82 | 88 | 91 | 51 | 52 | 54 | 56 | 59 | 45 | 39 | 41 | 40 | 4.545 | 4.656 | 4.768 | 4.88 | 4.991 | 5.107 | 2.799 | 2.865 | 2.931 | 0.14 | 0.14 | 0.14 | 0.14 | 0.14 | 0.14 | 0.14 | 0.14 | 0.14 | 0.14 | 0.14 | 0.14 | 0.221 |
| Percentage of IntangibleAssetsNetExcludingGoodwill | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 7.2 | 8.5 | 8.7 | 10.0 | 9.5 | 3.8 | 4.2 | 4.6 | 4.7 | 2.7 | 2.8 | 3.8 | 4.1 | 4.9 | 3.4 | 15.4 | 15.6 | 15.7 | 2.7 | 3.7 | 3.6 | 3.4 | 3.4 | 3.8 | 2.0 | 2.5 | 2.4 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.3 |
| 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 | 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 | 2015-12-31 |
| Value | 65 | 69 | 74 | 78 | 82 | 77 | 80 | 88 | 91 | 51 | 52 | 54 | 56 | 59 | 45 | 39 | 41 | 39 | 3.028 |
| Percentage of FiniteLivedIntangibleAssetsNet | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 2.5 | 3.0 | 3.2 | 3.7 | 3.5 | 3.7 | 4.1 | 4.6 | 4.7 | 2.7 | 2.8 | 3.8 | 4.1 | 4.9 | 3.4 | 15.4 | 15.6 | 15.0 | 2.3 |
| 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 | 2018-12-31 | 2016-09-30 |
| Value | 0.044 | 0.047 | 0.05 | 0.053 | 0.056 | 0.059 | 0.062 | 0.056 | 0.069 | 0.097 |
| Percentage of FiniteLivedIntangibleAssetsNet | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.2 |
| Percentage of Assets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Assets rily:AdvertisingRelationships | 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 | 2018-12-31 |
| Value | 0.087 | 0.095 | 0.103 | 0.107 | 0.116 | 0.125 | 0.133 | 0.116 | 0.152 |
| Percentage of FiniteLivedIntangibleAssetsNet | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.2 | 0.2 | 0.1 | 0.2 |
| Percentage of Assets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Assets rily:DomainNames | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 4.862 | 5.285 | 5.707 | 6.309 | 6.922 | 7.535 | 8.115 | 6.922 | 9.337 |
| Percentage of FiniteLivedIntangibleAssetsNet | 7.4 | 7.6 | 7.7 | 8.1 | 8.4 | 9.8 | 10.1 | 7.8 | 10.2 |
| Percentage of Assets | 0.2 | 0.2 | 0.2 | 0.3 | 0.3 | 0.4 | 0.4 | 0.4 | 0.5 |
| Percentage of Assets rily:InternallyDevelopedSoftwareAndOtherIntangibles | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2014-12-31 |
| Value | 58 | 61 | 65 | 68 | 71 | 66 | 68 | 71 | 75 | 34 | 2.805 | 2.916 | 3.028 | 1.059 |
| Percentage of FiniteLivedIntangibleAssetsNet | 89.5 | 89.4 | 88.0 | 87.7 | 87.4 | 85.6 | 85.3 | 81.1 | 82.9 | 89.2 | 0.0 | 0.0 | 100.0 | 0.0 |
| Percentage of Assets | 2.2 | 2.7 | 2.8 | 3.2 | 3.1 | 3.1 | 3.5 | 3.7 | 3.9 | 13.4 | 1.7 | 2.3 | 2.3 | 0.8 |
| Percentage of Assets us-gaap:CustomerRelationships | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 1.859 | 1.938 | 2.995 | 3.135 | 3.276 | 3.416 | 3.557 | 3.276 | 3.838 |
| Percentage of FiniteLivedIntangibleAssetsNet | 2.8 | 2.8 | 4.0 | 4.0 | 4.0 | 4.4 | 4.4 | 3.7 | 4.2 |
| Percentage of Assets | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.2 | 0.2 | 0.2 | 0.2 |
| Percentage of Assets us-gaap:Trademarks | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2014-06-30 | 2013-12-31 |
| Value | 4.098 | 31 | 12 | 12 |
| Percentage of DeferredTaxAssetsLiabilitiesNet | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 0.2 | 1.4 | 10.7 | 17.1 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 48 | 43 | 44 | 46 | 47 | 49 | 50 | 51 |
| Percentage of OperatingLeaseRightOfUseAsset | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 1.8 | 1.9 | 1.9 | 2.2 | 2.1 | 2.4 | 2.6 | 2.7 |
| 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 | 2014-12-31 |
| Value | 2722000.0 | 4226000.0 | 4301000.0 | 6858000.0 | 4477000.0 | 6239000.0 | 2136000.0 | 5217000.0 | 5646000.0 | 2278000.0 | 3790000.0 | 3180000.0 | 2650000.0 | 4046000.0 | 3184000.0 | 2498000.0 | 2703000.0 | 4188000.0 | 1084000.0 | 1466000.0 | 1123000.0 | 1093000.0 |
| 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 |
| Percentage of Assets | 0.1 | 0.2 | 0.2 | 0.3 | 0.2 | 0.3 | 0.1 | 0.3 | 0.3 | 0.1 | 0.2 | 0.2 | 0.2 | 0.3 | 0.2 | 1.0 | 1.0 | 1.6 | 0.6 | 1.2 | 0.8 | 0.8 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2014-12-31 |
| Value | 168 | 127 | 106 | 103 | 130 | 115 | 93 | 90 | 108 | 87 | 72 | 57 | 71 | 58 | 62 | 18 | 18 | 18 | 5.335 | 5.314 | 6.478 | 5.112 |
| Percentage of OtherAccruedLiabilitiesCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 6.3 | 5.5 | 4.6 | 4.9 | 5.6 | 5.5 | 4.7 | 4.7 | 5.6 | 4.6 | 3.9 | 4.0 | 5.2 | 4.8 | 4.7 | 7.2 | 7.0 | 7.0 | 3.1 | 4.2 | 4.9 | 3.7 |
| 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 | 2011-12-31 |
| Value | 26 | 26 | 26 | 27 | 29 | 0.552 | 0.71 | 0.558 | 0.602 | 0.762 | 0.854 | 0.122 | -0.184 | -0.047 | 1.061 | 0.954 | 1.045 | 1.091 | 1.078 | 1.004 | -0.118 | 1.832 | 0.677 | 0.772 | 0.018 | 0.098 | 0.146 | 0.276 | 0.012 | -0.052 | 0.463 | 0.526 | 0.928 | 0.732 | 0.927 | 0.0 |
| Percentage of MinorityInterest | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Percentage of Assets | 1.0 | 1.1 | 1.1 | 1.3 | 1.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -0.0 | -0.0 | 0.1 | 0.4 | 0.4 | 0.4 | 0.6 | 0.8 | -0.1 | 1.3 | 0.5 | 0.6 | 0.0 | 0.1 | 0.1 | 0.4 | 0.0 | -0.1 | 0.7 | 0.7 | 1.2 | 1.0 | 1.2 | 0.0 |
| Period End | 2021-03-02 |
| Value | 0.0024 |
| Percentage of MinorityInterest | 0.0 |
| Percentage of Assets | 0.0 |
| Percentage of Assets rily:DashMedicalHoldingsLLC | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2019-01-02 |
| Value | 60 | 55 | 57 | 59 | 61 | 63 | 65 | 65 | 67 |
| Percentage of OperatingLeaseLiability | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 2.3 | 2.4 | 2.5 | 2.8 | 2.7 | 3.0 | 3.3 | 3.4 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 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 | 2009-12-31 | 2008-12-31 |
| Value | 512 | 373 | 310 | 235 | 360 | 298 | 276 | 263 | 258 | 268 | 263 | 271 | 266 | 274 | 239 | 161 | 149 | 142 | 133 | 110 | 109 | 111 | 112 | 104 | 97 | 89 | 90 | -5.52 | -4.163 | -5.268 | -5.571 | -4.169 | -5.103 | -7.001 | -6.402 | -6.978 | -8.256 | -7.442 | -11.495 | -9.181 | -8.903 | -1.0 | 14 |
| 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 | 19.3 | 16.3 | 13.5 | 11.0 | 15.6 | 14.2 | 14.0 | 13.7 | 13.2 | 14.0 | 14.0 | 19.0 | 19.2 | 22.4 | 17.8 | 63.2 | 56.4 | 54.5 | 78.6 | 87.3 | 82.6 | 78.1 | 76.3 | 76.8 | 69.8 | 77.1 | 74.5 | -8.8 | -5.7 | -8.0 | -8.2 | -5.4 | -6.3 | -9.6 | -8.5 | -8.9 | -10.8 | -8.1 | -16.9 | 0.0 | -12.3 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 | 2009-12-31 |
| Value | 538 | 399 | 336 | 263 | 390 | 299 | 277 | 263 | 258 | 269 | 264 | 271 | 265 | 274 | 240 | 162 | 150 | 143 | 134 | 111 | 109 | 112 | 113 | 105 | 97 | 89 | 90 | -5.244 | -4.151 | -5.32 | -5.108 | -3.643 | -4.175 | -6.269 | -5.475 | -6.978 | -8.256 | -7.442 | -11.495 | -8.903 | -1.0 |
| Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 20.2 | 17.4 | 14.6 | 12.3 | 16.8 | 14.2 | 14.0 | 13.8 | 13.2 | 14.0 | 14.1 | 19.0 | 19.2 | 22.4 | 17.9 | 63.5 | 56.8 | 54.9 | 79.3 | 88.1 | 82.6 | 79.4 | 76.8 | 77.3 | 69.8 | 77.2 | 74.7 | -8.3 | -5.6 | -8.1 | -7.5 | -4.7 | -5.2 | -8.6 | -7.3 | -8.9 | -10.8 | -8.1 | -16.9 | -12.3 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 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 | -0.823 | -2.167 | -2.693 | -3.208 | -1.988 | -2.345 | -1.824 | -1.991 | -2.161 | -1.696 | -1.619 | -0.754 | -0.534 | -0.321 | -0.666 | -1.067 | -1.712 | -1.098 | -1.075 | -0.993 | -1.058 | -0.935 | -0.656 | -0.727 | -0.648 | -0.627 | -0.658 | -0.661 | -0.638 | -0.809 | -0.746 | -0.875 | -0.52 | -0.036 | 0.016 | -0.036 | -0.247 | -0.087 | -0.123 | 0.007 |
| Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest | -0.2 | -0.5 | -0.8 | -1.2 | -0.5 | -0.8 | -0.7 | -0.8 | -0.8 | -0.6 | -0.6 | -0.3 | -0.2 | -0.1 | -0.3 | -0.7 | -1.1 | -0.8 | -0.8 | -0.9 | -1.0 | -0.8 | -0.6 | -0.7 | -0.7 | -0.7 | -0.7 | 12.6 | 15.4 | 15.2 | 14.6 | 24.0 | 12.5 | 0.6 | -0.3 | 0.5 | 3.0 | 1.2 | 1.1 | -0.1 |
| Percentage of Assets | -0.0 | -0.1 | -0.1 | -0.2 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | -0.0 | -0.0 | -0.0 | -0.4 | -0.6 | -0.4 | -0.6 | -0.8 | -0.8 | -0.7 | -0.4 | -0.5 | -0.5 | -0.5 | -0.5 | -1.1 | -0.9 | -1.2 | -1.1 | -1.1 | -0.6 | -0.0 | 0.0 | -0.0 | -0.3 | -0.1 | -0.2 | 0.0 |
| Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 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 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 | 2009-12-31 |
| Value | 310 | 332 | 306 | 308 | 323 | 259 | 255 | 257 | 258 | 255 | 244 | 261 | 259 | 259 | 220 | 143 | 141 | 141 | 140 | 117 | 116 | 116 | 115 | 115 | 110 | 99 | 99 | 3.082 | 3.082 | 3.082 | 3.082 | 3.082 | 3.082 | 3.082 | 3.082 | 3.177 | 3.177 | 3.177 | 3.191 | 2.878 | -0.249 |
| Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest | 57.6 | 83.0 | 91.2 | 117.3 | 82.8 | 86.6 | 92.3 | 97.7 | 100.0 | 94.8 | 92.6 | 96.2 | 97.8 | 94.3 | 91.9 | 88.4 | 93.9 | 98.5 | 104.6 | 105.4 | 106.8 | 103.0 | 102.2 | 109.7 | 113.9 | 111.3 | 110.2 | -58.8 | -74.2 | -57.9 | -60.3 | -84.6 | -73.8 | -49.2 | -56.3 | -45.5 | -38.5 | -42.7 | -27.8 | -32.3 | 24.9 |
| Percentage of Assets | 11.7 | 14.4 | 13.4 | 14.5 | 13.9 | 12.3 | 12.9 | 13.4 | 13.2 | 13.3 | 13.0 | 18.3 | 18.7 | 21.1 | 16.4 | 56.2 | 53.3 | 54.1 | 82.9 | 92.9 | 88.2 | 81.8 | 78.5 | 84.8 | 79.6 | 85.9 | 82.3 | 4.9 | 4.2 | 4.7 | 4.5 | 4.0 | 3.8 | 4.2 | 4.1 | 4.0 | 4.2 | 3.5 | 4.7 | 4.0 | 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 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 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 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 | 2009-12-31 |
| Value | 0.003 | 0.003 | 0.003 | 0.003 | 0.003 | 0.003 | 0.003 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.002 | 0.004 | 0.004 | 0.004 | 0.004 | 0.004 | 0.004 | 0.004 | 0.004 | 0.004 | 0.004 | 0.004 | 0.004 | 0.004 | 0.003 |
| Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | -0.0 | -0.1 | -0.0 | -0.0 | -0.3 |
| 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 |
| 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 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 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 | 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 | 26 | 26 | 26 | 27 | 29 | 0.552 | 0.71 | 0.558 | 0.602 | 0.762 | 0.854 | 0.122 | -0.184 | -0.047 | 1.061 | 0.954 | 1.045 | 1.091 | 1.078 | 1.004 | -0.118 | 1.832 | 0.677 | 0.772 | 0.018 | 0.098 | 0.146 | 0.276 | 0.012 | -0.052 | 0.463 | 0.526 | 0.928 | 0.732 | 0.927 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest | 4.9 | 6.5 | 7.8 | 10.6 | 7.6 | 0.2 | 0.3 | 0.2 | 0.2 | 0.3 | 0.3 | 0.0 | -0.1 | -0.0 | 0.4 | 0.6 | 0.7 | 0.8 | 0.8 | 0.9 | -0.1 | 1.6 | 0.6 | 0.7 | 0.0 | 0.1 | 0.2 | -5.3 | -0.3 | 1.0 | -9.1 | -14.4 | -22.2 | -11.7 | -16.9 | -0.0 | -0.0 | -0.0 | -0.0 | -0.0 |
| Percentage of Assets | 1.0 | 1.1 | 1.1 | 1.3 | 1.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -0.0 | -0.0 | 0.1 | 0.4 | 0.4 | 0.4 | 0.6 | 0.8 | -0.1 | 1.3 | 0.5 | 0.6 | 0.0 | 0.1 | 0.1 | 0.4 | 0.0 | -0.1 | 0.7 | 0.7 | 1.2 | 1.0 | 1.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Assets us-gaap:NoncontrollingInterest | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 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 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 | 2009-12-31 |
| Value | 203 | 43 | 5.927 | -70.232 | 39 | 41 | 22 | 7.468 | 1.579 | 14 | 20 | 10 | 6.582 | 15 | 19 | 18 | 9.887 | 2.21 | -6.158 | -6.057 | -6.305 | -4.323 | -2.523 | -10.209 | -12.891 | -9.59 | -8.722 | -7.945 | -6.611 | -7.545 | -7.911 | -6.38 | -7.669 | -10.051 | -9.504 | -10.123 | -11.19 | -10.536 | -14.567 | -11.792 | -0.754 |
| Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest | 37.7 | 11.0 | 1.8 | -26.7 | 10.1 | 14.0 | 8.1 | 2.8 | 0.6 | 5.5 | 7.7 | 4.0 | 2.5 | 5.8 | 7.9 | 11.7 | 6.6 | 1.5 | -4.6 | -5.4 | -5.8 | -3.8 | -2.2 | -9.7 | -13.3 | -10.7 | -9.7 | 151.5 | 159.3 | 141.8 | 154.9 | 175.1 | 183.7 | 160.3 | 173.6 | 145.1 | 135.5 | 141.6 | 126.7 | 132.4 | 75.4 |
| Percentage of Assets | 7.6 | 1.9 | 0.3 | -3.3 | 1.7 | 2.0 | 1.1 | 0.4 | 0.1 | 0.8 | 1.1 | 0.8 | 0.5 | 1.3 | 1.4 | 7.4 | 3.7 | 0.8 | -3.6 | -4.8 | -4.8 | -3.0 | -1.7 | -7.5 | -9.3 | -8.3 | -7.2 | -12.6 | -9.0 | -11.5 | -11.7 | -8.2 | -9.5 | -13.8 | -12.7 | -12.8 | -14.7 | -11.5 | -21.4 | -16.3 | 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 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 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 | 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 | 3000.0 | 3000.0 | 3000.0 | 3000.0 | 3000.0 | 3000.0 | 3000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 2000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 | 4000.0 |
| 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 |
| 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 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 310 | 332 | 306 | 308 | 323 | 259 | 255 | 257 | 258 | 255 | 244 | 261 | 259 | 259 | 220 | 143 | 141 | 141 | 140 | 117 | 116 | 116 | 115 | 115 | 110 | 99 | 99 | 3.082 | 3.082 | 3.082 | 3.082 | 3.082 | 3.082 | 3.082 | 3.082 | 3.177 | 3.177 | 3.177 | 3.191 | 2.878 |
| Percentage of AdditionalPaidInCapital | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of Assets | 11.7 | 14.4 | 13.4 | 14.5 | 13.9 | 12.3 | 12.9 | 13.4 | 13.2 | 13.3 | 13.0 | 18.3 | 18.7 | 21.1 | 16.4 | 56.2 | 53.3 | 54.1 | 82.9 | 92.9 | 88.2 | 81.8 | 78.5 | 84.8 | 79.6 | 85.9 | 82.3 | 4.9 | 4.2 | 4.7 | 4.5 | 4.0 | 3.8 | 4.2 | 4.1 | 4.0 | 4.2 | 3.5 | 4.7 | 4.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2010-12-31 |
| Value | 203 | 43 | 5.927 | -70.232 | 39 | 41 | 22 | 7.468 | 1.579 | 14 | 20 | 10 | 6.582 | 15 | 19 | 18 | 9.887 | 2.21 | -6.158 | -6.057 | -6.305 | -4.323 | -2.523 | -10.209 | -12.891 | -9.59 | -8.722 | -7.945 | -6.611 | -7.545 | -7.911 | -6.38 | -7.669 | -10.051 | -9.504 | -10.123 | -11.19 | -10.536 | -14.567 | -11.792 |
| 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 |
| Percentage of Assets | 7.6 | 1.9 | 0.3 | -3.3 | 1.7 | 2.0 | 1.1 | 0.4 | 0.1 | 0.8 | 1.1 | 0.8 | 0.5 | 1.3 | 1.4 | 7.4 | 3.7 | 0.8 | -3.6 | -4.8 | -4.8 | -3.0 | -1.7 | -7.5 | -9.3 | -8.3 | -7.2 | -12.6 | -9.0 | -11.5 | -11.7 | -8.2 | -9.5 | -13.8 | -12.7 | -12.8 | -14.7 | -11.5 | -21.4 | -16.3 |
| 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 | 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 | -823000.0 | -2167000.0 | -2693000.0 | -3208000.0 | -1988000.0 | -2345000.0 | -1824000.0 | -1991000.0 | -2161000.0 | -1696000.0 | -1619000.0 | -754000.0 | -534000.0 | -321000.0 | -666000.0 | -1067000.0 | -1712000.0 | -1098000.0 | -1075000.0 | -993000.0 | -1058000.0 | -935000.0 | -656000.0 | -727000.0 | -648000.0 | -627000.0 | -658000.0 | -661000.0 | -638000.0 | -809000.0 | -746000.0 | -875000.0 | -520000.0 | -36000.0 | 16000.0 | -36000.0 | -247000.0 | -87000.0 | -123000.0 | 7000.0 |
| Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | -0.1 | -0.1 | -0.2 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | -0.0 | -0.0 | -0.0 | -0.4 | -0.6 | -0.4 | -0.6 | -0.8 | -0.8 | -0.7 | -0.4 | -0.5 | -0.5 | -0.5 | -0.5 | -1.1 | -0.9 | -1.2 | -1.1 | -1.1 | -0.6 | -0.0 | 0.0 | -0.0 | -0.3 | -0.1 | -0.2 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 |
| Value | 26 | 26 | 26 | 27 | 29 | 0.552 | 0.71 | 0.558 | 0.602 | 0.762 | 0.854 | 0.122 | -0.184 | -0.047 | 1.061 | 0.954 | 1.045 | 1.091 | 1.078 | 1.004 | -0.118 | 1.832 | 0.677 | 0.772 | 0.018 | 0.098 | 0.146 | 0.276 | 0.012 | -0.052 | 0.463 | 0.526 | 0.928 | 0.732 | 0.927 | 0.0 |
| Percentage of MinorityInterest | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Percentage of Assets | 1.0 | 1.1 | 1.1 | 1.3 | 1.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -0.0 | -0.0 | 0.1 | 0.4 | 0.4 | 0.4 | 0.6 | 0.8 | -0.1 | 1.3 | 0.5 | 0.6 | 0.0 | 0.1 | 0.1 | 0.4 | 0.0 | -0.1 | 0.7 | 0.7 | 1.2 | 1.0 | 1.2 | 0.0 |
| Period End | 2021-03-02 |
| Value | 0.0024 |
| Percentage of MinorityInterest | 0.0 |
| Percentage of Assets | 0.0 |
| Percentage of Assets rily:DashMedicalHoldingsLLC | 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 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 |
| Value | 4.778 | 4.168 | 5.321 | 5.64 | 4.728 | 2.934 | 2.614 | 4.392 | 3.091 | 3.001 | 2.558 | 2.662 | 3.739 | 3.033 | 0.907 | 0.937 | 0.834 | 0.56 | 0.437 | 0.91 | 0.752 | 0.0 | 0.01 | 0.063 | 0.358 |
| 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 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 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 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 |
| Value | 4.778 | 4.168 | 5.321 | 5.64 | 4.728 | 2.934 | 2.614 | 4.392 | 3.091 | 3.001 | 2.558 | 2.662 | 3.739 | 3.033 | 0.907 | 0.937 | 0.834 | 0.56 | 0.437 | 0.91 | 0.752 | 0.0 | 0.01 | 0.063 | 0.358 |
| 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 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 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 |
| 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 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2017-12-31 |
| Value | 603000.0 | 601000.0 | 465000.0 | 0 |
| Percentage of MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders | 100.0 | 100.0 | 100.0 | 0.0 |
| Percentage of Assets | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2017-12-31 |
| Value | 603000.0 | 601000.0 | 465000.0 | 0 |
| Percentage of MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders | 100.0 | 100.0 | 100.0 | 0.0 |
| Percentage of Assets | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of Assets us-gaap:NoncontrollingInterest | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 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 | -29.208 | 73 | 12 | 0.455 | -76.615 | 44 | -7.486 | 8.924 | -25.919 | 129 | -154.711 | -54.055 | -33.011 | 34 | -43.965 | -38.855 | 52 | -2.104 | -7.584 | 7.65 | 0.633 | 1.638 | 6.431 | 7.508 | 3.645 | -2.547 | -2.981 | -0.162 | -0.433 | 6.646 |
| Percentage of NetCashProvidedByUsedInOperatingActivities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 109649.3 | 5793.3 | 185.0 | -30893.1 | 12405.8 | -2261.6 | 1400.9 | -4393.1 | 29382.6 | -93199.4 | -42230.5 | -198.0 | 44790.8 | -29310.0 | -29435.6 | 18305.6 | 0.0 | 0.0 | 0.0 | 0.0 | 1840.4 | 1942.9 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 | 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 | -29.9 | -15.989 | -11.065 | -71.492 | -43.952 | -23.868 | -201.063 | -26.513 | -104.892 | -42.87 | 0.589 | -4.268 | -10.706 | -30.271 | 4.235 | 3.12 | 75 | -99.789 | -12.065 | -0.019 | 0.028 | 0.353 | -1.973 | -1.431 | 7.642 | -1.318 | -3.682 | -1.363 | -0.401 | 4.475 | -3.143 | -2.6 | 2.508 | 0.802 | -1.172 |
| Percentage of NetCashProvidedByUsedInInvestingActivities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | -23864.2 | -4939.7 | -29061.8 | -17722.6 | -6611.6 | -60744.1 | -4162.2 | -17778.3 | -9699.1 | 354.8 | -3334.4 | -64.2 | -39830.3 | 2823.3 | 2363.6 | 26224.1 | -383803.8 | -402166.7 | -633.3 | 400.0 | 7060.0 | 0.0 | 0.0 | 0.0 | 0.0 | -4137.1 | -411.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 | 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 | -8.045 | 5.774 | -20.517 | 92 | 53 | 92 | 95 | 8.241 | 76 | -44.059 | 248 | 3.813 | 75 | -7.032 | 72 | -6.841 | -39.982 | 60 | 21 | -2.187 | -3.496 | -3.72 | -2.895 | -1.608 | -2.366 | 0.572 | -2.824 | -2.157 | -1.479 | -9.275 | 4.717 | 1.083 | -0.526 | -1.294 | -10.948 |
| Percentage of NetCashProvidedByUsedInFinancingActivities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 8617.9 | -9159.4 | 37533.3 | 21771.0 | 25517.2 | 28950.5 | 1293.7 | 13011.4 | -9968.1 | 149601.2 | 2978.9 | 452.2 | -9252.6 | 48394.7 | -5182.6 | -13979.7 | 233038.5 | 732766.7 | -72900.0 | -49942.9 | -74400.0 | 0.0 | 0.0 | 0.0 | 0.0 | -3173.0 | -651.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 | 2019-09-30 |
| Value | -66.249 | 64 | -66.319 | 112 |
| Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 96062.7 | -26741.5 | 31250.4 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 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 | 44 | 31 | -10.086 | -4.254 | 4.516 | -0.072 | 6.82 | -0.39 | 1.983 | 0.0 | 29 | -0.924 | -14.512 | -9.124 | 1.71 | 1.568 | 0.119 | 0.152 | 1.158 | -0.048 | 3.789 | 1.71 | -1.119 | -0.455 | -0.595 | -0.815 | 1.067 | -0.117 | -0.968 | 1.007 | 1.478 | -0.266 | -0.424 | 0.578 | 0.136 | 1.894 | -0.86 | 0.701 | -0.161 | 0.874 |
| Percentage of DeferredIncomeTaxExpenseBenefit | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 | 2011-09-30 | 2011-06-30 |
| Value | 4.604 | 4.886 | 4.923 | 4.956 | 4.831 | 4.473 | 4.831 | 4.913 | 4.041 | 3.098 | 3.333 | 3.337 | 3.435 | 3.415 | 2.248 | 2.042 | 1.925 | 1.982 | 0.084 | 0.203 | -0.217 | 0.213 | 0.11 | 0.158 | 0.153 | 0.161 | 0.169 | 0.186 | 0.185 |
| 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 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-03-31 |
| Value | 0.0 | 0.001 | 0.002 | 0.001 | 0.002 | 0.002 | 0.008 |
| Percentage of DepreciationDepletionAndAmortization | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.2 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | 0.715 | 0.714 | 0.715 | 0.714 |
| Percentage of DepreciationDepletionAndAmortization | 15.5 | 14.6 | 14.5 | 14.4 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-03-31 |
| Value | 0.904 | 1.166 | 1.091 | 1.014 | 1.281 | 1.287 | 1.276 | 1.564 |
| Percentage of DepreciationDepletionAndAmortization | 19.6 | 23.9 | 22.2 | 21.0 | 28.6 | 26.6 | 26.0 | 46.9 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 2.545 | 2.736 | 2.851 | 2.939 | 2.956 | 3.3 |
| Percentage of DepreciationDepletionAndAmortization | 55.3 | 56.0 | 57.9 | 60.8 | 66.1 | 68.3 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-03-31 |
| Value | 0.051 | 0.047 | 0.036 | 0.031 | 0.033 | 0.049 |
| Percentage of DepreciationDepletionAndAmortization | 1.0 | 1.0 | 0.8 | 0.6 | 0.7 | 1.5 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | 0.848 | 2.265 | -11.927 | -15.674 | 25 | -13.775 | 19 | 2.845 | -23.034 | -172.676 | 200 | 8.078 |
| 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 |
| 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 | 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 | -29.208 | 73 | 12 | 0.455 | -76.615 | 44 | -7.486 | 8.924 | -25.919 | 129 | -154.711 | -54.055 | -33.011 | 34 | -43.965 | -38.855 | 52 | -2.104 | -7.584 | 7.65 | 0.633 | 1.638 | 6.431 | 7.508 | 3.645 | -2.547 | -2.981 | -0.162 | -0.433 | 6.646 |
| Percentage of NetCashProvidedByUsedInOperatingActivities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 109649.3 | 5793.3 | 185.0 | -30893.1 | 12405.8 | -2261.6 | 1400.9 | -4393.1 | 29382.6 | -93199.4 | -42230.5 | -198.0 | 44790.8 | -29310.0 | -29435.6 | 18305.6 | 0.0 | 0.0 | 0.0 | 0.0 | 1840.4 | 1942.9 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 | 170 | 48 | 83 | -98.665 | 17 | 34 | 22 | 8.023 | -8.805 | 2.814 | 16 | 4.503 | -6.113 | 0.368 | 3.28 | 14 | 12 | 8.939 | -0.101 | 0.248 | -1.004 | 1.463 | 8.664 | 2.682 | -2.822 | -0.868 | -0.777 | -1.334 | 0.934 | 0.366 | -1.531 | 1.289 | 2.382 | -0.547 | 0.619 | 1.067 | -0.654 | 4.031 | -2.249 | -0.526 | -1.906 | 0.455 | -6.607 |
| Percentage of NetIncomeLoss | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 72207.5 | 37428.6 | -40107.7 | 6906.9 | 9501.9 | 6694.0 | 1259.5 | -1492.4 | 636.7 | 10239.2 | 3518.0 | -36.7 | 484.2 | 2186.7 | 10622.0 | 4349.7 | 34380.8 | -3366.7 | 8266.7 | -14342.9 | 29260.0 | 288800.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -614.6 | 187.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 | 171 | 48 | 82 | -99.249 | 17 | 34 | 22 | 7.979 | -8.965 | 2.722 | 17 | 4.842 | -5.451 | 0.122 | 3.363 | 13 | 23 | 8.374 | -0.027 | 1.37 | -1.046 | 2.618 | 8.569 | 3.436 | -2.902 | -0.916 | -0.907 | -1.07 | 1.0 | 0.236 | -1.595 | 0.935 | 2.576 | -0.767 | 1.464 | 1.067 | -0.654 | 4.031 | -2.249 | -0.526 |
| 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 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 InterestIncomeOperating | 0.0 | 72973.1 | 36843.3 | -40345.1 | 7062.9 | 9458.2 | 6739.9 | 1252.6 | -1519.5 | 615.8 | 10723.5 | 3782.8 | -32.7 | 160.5 | 2242.0 | 10531.1 | 8045.1 | 32207.7 | -900.0 | 45666.7 | -14942.9 | 52360.0 | 285633.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -861.8 | 442.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 171 | 48 | 82 | 17 | 34 | 22 |
| Percentage of ProfitLoss | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 72973.1 | 36843.3 | 7062.9 | 9458.2 | 6739.9 |
| Percentage of InterestIncomeOperating us-gaap:CorporateAndOther | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 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 |
| Value | 0.513 | -1.311 | -0.158 | 0.152 | -0.044 | -0.16 | -0.092 | 0.732 | 0.306 | -0.137 | -0.186 | 0.107 | -0.091 | -0.046 | 0.013 | 0.074 | 1.122 | -0.042 | 1.155 | -0.095 | 0.754 | -0.08 | -0.048 | -0.13 | 0.264 | 0.066 | -0.13 | -0.064 | -0.354 | 0.194 | -0.22 |
| Percentage of ProfitLoss | 1.0 | -1.6 | -0.5 | 0.7 | -0.6 | 1.8 | -3.4 | 4.1 | 6.3 | 2.5 | -152.5 | 3.2 | -0.7 | -0.2 | 0.2 | -274.1 | 81.9 | 4.0 | 44.1 | -1.1 | 21.9 | 2.8 | 5.2 | 14.3 | -24.7 | 6.6 | -55.1 | 4.0 | -37.9 | 7.5 | 28.7 |
| Percentage of InterestIncomeOperating | 765.7 | -585.3 | -43.8 | 45.9 | -6.9 | -27.1 | -20.8 | 441.0 | 239.1 | -0.8 | -244.7 | 71.3 | -68.9 | -16.1 | 50.0 | 2466.7 | 37400.0 | -600.0 | 23100.0 | -3166.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -247.2 |
| Percentage of InterestIncomeOperating us-gaap:NoncontrollingInterest | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 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 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 |
| Value | 48 | 83 | 34 | 22 | 8.023 | -8.805 | 2.814 | 16 | 4.503 | -6.113 | 0.368 | 3.28 | 14 | 12 | 8.939 | -0.101 | 0.248 | -1.004 | 1.463 | 8.664 | 2.682 | -2.822 | -0.868 | -0.777 | -1.334 | 0.934 | 0.366 | -1.531 | 1.289 | 2.382 | -0.547 | 0.619 | 1.067 | -0.654 | 4.031 |
| Percentage of ProfitLoss | 99.0 | 101.6 | 100.5 | 99.3 | 100.6 | 98.2 | 103.4 | 95.5 | 93.0 | 112.1 | 301.6 | 97.5 | 100.9 | 54.1 | 106.7 | 374.1 | 18.1 | 96.0 | 55.9 | 101.1 | 78.1 | 97.2 | 94.8 | 85.7 | 124.7 | 93.4 | 155.1 | 96.0 | 137.9 | 92.5 | 71.3 | 42.3 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 72207.5 | 37428.6 | 9501.9 | 6694.0 | 1259.5 | -1492.4 | 636.7 | 10239.2 | 3518.0 | -36.7 | 484.2 | 2186.7 | 10622.0 | 4349.7 | 34380.8 | -3366.7 | 8266.7 | -14342.9 | 29260.0 | 288800.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -614.6 | 187.0 | 0.0 | 0.0 | 0.0 |
| Percentage of InterestIncomeOperating 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 | 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 | 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 | 2012-12-31 | 2012-09-30 | 2011-12-31 | 2011-09-30 | 2010-12-31 | 2010-09-30 |
| Value | 4.321 | 4.778 | 4.167 | 5.322 | 5.64 | 4.728 | 2.934 | 2.614 | 4.392 | 3.091 | 3.001 | 2.558 | 2.662 | 3.739 | 3.033 | 0.907 | 0.937 | 0.834 | 0.56 | 0.437 | 0.851 | 0.776 | 0.0 | 0.0 | 0.0 | 0.01 | 0.99 | 1.032 |
| Percentage of ShareBasedCompensation | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 |
| Value | -2.319 | 4.68 | 4.109 | 4.109 | 4.461 | 3.604 | 1.835 | 1.726 | 1.744 | 1.714 | 1.261 | 1.11 | 1.37 | 1.41 | 1.305 | 0.907 | 0.937 | 0.834 |
| Percentage of ShareBasedCompensation | -53.7 | 97.9 | 98.6 | 77.2 | 79.1 | 76.2 | 62.5 | 66.0 | 39.7 | 55.5 | 42.0 | 43.4 | 51.5 | 37.7 | 43.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 0.096 | 0.059 | 0.165 | 0.059 | 0.068 | 0.074 | 0.121 |
| Percentage of ShareBasedCompensation | 2.0 | 1.4 | 3.1 | 1.0 | 1.4 | 2.5 | 4.6 |
| 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 | 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 | -29.9 | -15.989 | -11.065 | -71.492 | -43.952 | -23.868 | -201.063 | -26.513 | -104.892 | -42.87 | 0.589 | -4.268 | -10.706 | -30.271 | 4.235 | 3.12 | 75 | -99.789 | -12.065 | -0.019 | 0.028 | 0.353 | -1.973 | -1.431 | 7.642 | -1.318 | -3.682 | -1.363 | -0.401 | 4.475 | -3.143 | -2.6 | 2.508 | 0.802 | -1.172 |
| Percentage of NetCashProvidedByUsedInInvestingActivities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | -23864.2 | -4939.7 | -29061.8 | -17722.6 | -6611.6 | -60744.1 | -4162.2 | -17778.3 | -9699.1 | 354.8 | -3334.4 | -64.2 | -39830.3 | 2823.3 | 2363.6 | 26224.1 | -383803.8 | -402166.7 | -633.3 | 400.0 | 7060.0 | 0.0 | 0.0 | 0.0 | 0.0 | -4137.1 | -411.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 | 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 | -8.045 | 5.774 | -20.517 | 92 | 53 | 92 | 95 | 8.241 | 76 | -44.059 | 248 | 3.813 | 75 | -7.032 | 72 | -6.841 | -39.982 | 60 | 21 | -2.187 | -3.496 | -3.72 | -2.895 | -1.608 | -2.366 | 0.572 | -2.824 | -2.157 | -1.479 | -9.275 | 4.717 | 1.083 | -0.526 | -1.294 | -10.948 |
| Percentage of NetCashProvidedByUsedInFinancingActivities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of InterestIncomeOperating | 0.0 | 8617.9 | -9159.4 | 37533.3 | 21771.0 | 25517.2 | 28950.5 | 1293.7 | 13011.4 | -9968.1 | 149601.2 | 2978.9 | 452.2 | -9252.6 | 48394.7 | -5182.6 | -13979.7 | 233038.5 | 732766.7 | -72900.0 | -49942.9 | -74400.0 | 0.0 | 0.0 | 0.0 | 0.0 | -3173.0 | -651.7 | 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 | 12 | 8.333 | 7.88 | 9.609 | 16 | 15 | 7.385 | 2.606 |
| Percentage of PaymentsOfDividendsCommonStock | 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 |
| Value | 9.9 | 10 | 3.711 | 24 | 0.0 | 1.021 | 0.602 | 2.65 | 1.365 | 0.0 |
| Percentage of PaymentsForRepurchaseOfCommonStock | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 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 |
| Value | 3.4 | 2.9 | 0.0293 | 0.0374 | 0.0455 | 0.0505 | 0.0549 | 0.055 | 0.0551 |
| Percentage of DebtInstrumentInterestRateStatedPercentage | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations rily:BRPIAcquisitionCoLLC rily:TermLoan rily:BRPACCreditAgreement | 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 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-05-31 |
| Value | 7.5 | 7.5 | 0.075 | 0.075 | 0.075 | 0.075 | 0.075 | 0.075 | 0.075 | 0.075 | 0.075 | 0.075 |
| Percentage of DebtInstrumentInterestRateStatedPercentage | 220.6 | 258.6 | 256.0 | 136.6 | 136.4 | 136.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations | 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 LongTermDebtAndCapitalLeaseObligations rily:SeniorNotes1 | 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 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 |
| Value | 7.25 | 7.25 | 0.0725 | 0.0725 | 0.0725 | 0.0725 | 0.0725 | 0.0725 | 0.0725 | 0.0725 |
| Percentage of DebtInstrumentInterestRateStatedPercentage | 213.2 | 250.0 | 247.4 | 132.1 | 131.8 | 131.6 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations rily:SeniorNotes4 | 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 | 2019-06-30 |
| Value | 7.375 | 7.375 | 0.07375 | 0.0725 |
| Percentage of DebtInstrumentInterestRateStatedPercentage | 216.9 | 254.3 | 251.7 | 132.1 |
| Percentage of LongTermDebtAndCapitalLeaseObligations | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations rily:SeniorNotes5 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 |
| Value | 6.875 | 6.875 | 0.06875 | 0.06875 | 0.06875 | 0.06875 | 0.06875 |
| Percentage of DebtInstrumentInterestRateStatedPercentage | 202.2 | 237.1 | 234.6 | 125.2 | 125.0 | 124.8 | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations rily:SeniorNotes7 | 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 |
| Value | 6.375 | 6.375 | 0.06375 |
| Percentage of DebtInstrumentInterestRateStatedPercentage | 187.5 | 219.8 | 217.6 |
| Percentage of LongTermDebtAndCapitalLeaseObligations | 0.0 | 0.0 | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations rily:SeniorNotesEight | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 |
| Value | 6.5 | 6.5 | 0.065 |
| Percentage of DebtInstrumentInterestRateStatedPercentage | 191.2 | 224.1 | 221.8 |
| Percentage of LongTermDebtAndCapitalLeaseObligations | 0.0 | 0.0 | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations rily:SeniorNotesSeven | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | 6.75 | 6.75 | 0.0675 | 0.0675 |
| Percentage of DebtInstrumentInterestRateStatedPercentage | 198.5 | 232.8 | 230.4 | 180.5 |
| Percentage of LongTermDebtAndCapitalLeaseObligations | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations rily:SixPointSevenFivePercentSeniorNotes | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-01-25 |
| Value | 6.0 |
| Percentage of DebtInstrumentInterestRateStatedPercentage | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations | 0.0 |
| Percentage of LongTermDebtAndCapitalLeaseObligations rily:SeniorNotesTwentyTwentyEight us-gaap:SubsequentEvent | 0.0 |
| Period End | 2020-12-31 |
| Value | 34 |
| Percentage of DeferredTaxLiabilities | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 |
| Value | 10 | 10 | 11 | 1.14 |
| Percentage of UnrecognizedTaxBenefits | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 |
| Value | 78 | 77 | 77 | 2.582 | 4.9 |
| Percentage of DeferredTaxAssetsValuationAllowance | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-11-11 |
| Value | 7500000.0 |
| Percentage of AdditionalPurchaseOfValue | 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 | 2018-12-31 | 2018-09-30 | 2018-06-30 |
| Value | -169000.0 | 38000.0 | 338000.0 | 72000.0 | 1478000.0 | 246000.0 | 430000.0 | 826000.0 | 0 | 147000.0 |
| Percentage of CapitalizedCosts | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 |
| Value | 90 | 138 | 70 | 52 |
| Percentage of ConsolidatedOperatinglossIncomeFromReportableSegments | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | 6.5 | 0.0 | 0.0 | 4.633 |
| Percentage of ConversionOfLoansReceivable | 100.0 | 0.0 | 0.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 16 |
| Percentage of ConversionOfLoansReceivableSharesOfStock | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | -10821000.0 | -6942000.0 | -7597000.0 | -4349000.0 | -10617000.0 | -8482000.0 |
| Percentage of CorporateAndOtherExpenses | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 9.25 | 23 | 7.985 | 17 | 7.936 | 19 |
| Percentage of DirectCostOfService | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-03-31 |
| Value | -4.324 | -18.373 | -3.217 | -11.712 | -2.371 | -12.939 | -6.274 | -4.576 |
| Percentage of DirectCostOfServices | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | -4.926 | -4.891 | -4.768 | -5.398 | -5.565 | -6.724 |
| Percentage of DirectCostOfServices | 113.9 | 26.6 | 148.2 | 46.1 | 234.7 | 52.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 0.199 | -0.22 | 4.049 | 17 | 25 | -7.704 | -5.688 | 0.049 |
| Percentage of FairValueAdjustmentsNoncash | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-11-30 |
| Value | 441.0 |
| Percentage of FinancialAdvisoryFees | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 0.05 | 1.507 | 8.504 | 4.046 | 0.041 | 0.017 | -0.432 | 0.088 |
| Percentage of ImpairmentOfIntangiblesAndGainOnDisposalOfFixedAssets | 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 |
| Value | 0.0 | 0.0 | 8.5 | 4.0 |
| Percentage of ImpairmentOfTradenames | 0.0 | 0.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | 0.0 | 0.0 | -8.5 | -4.0 |
| Percentage of ImpairmentOfTradenames | 0.0 | 0.0 | -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 |
| Value | 294 | 56 | 105 | -125.061 | 120 | 48 | -18.512 | 15 | 51 | 61 | 9.723 | 5.457 | 40 | 0.375 | 16 | 24 | 7.551 | -15.616 |
| Percentage of IncreaseDecreaseSecuritiesAndOtherInvestmentsOwned | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2020-08-10 |
| Value | 29 |
| Percentage of IndemnityAmount | 100.0 |
| Period End | 2020-08-26 |
| Value | 600000.0 |
| Percentage of IndemnityRiderReceived | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 |
| Value | 545000.0 | 445000.0 | 419000.0 | 853000.0 | 552000.0 |
| Percentage of InterestExpenseFromLoanParticipations | 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 |
| Value | 11 | 10 | 11 | 8.473 | 9.565 | 10 | 5.502 | 6.804 | 6.722 | 6.425 | 4.724 | 5.168 | 5.536 | 4.95 | 1.565 |
| Percentage of InterestExpenseSecuritiesLending | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-03-31 |
| Value | 11 | 10 | -11.221 | 9.565 | 10 | -5.502 | -6.804 | -5.168 |
| Percentage of InterestExpenseSecuritiesLending | 100.0 | 100.0 | -100.0 | 100.0 | 100.0 | -100.0 | -100.0 | -100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 30 | 26 | 24 | 23 | 25 | 16 |
| Percentage of InterestIncomeLoanAndSecuritiesLending | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 30 | 26 | 24 | 23 | 25 | 16 |
| Percentage of InterestIncomeLoansAndSecuritiesLending | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 4.5 | 0.0 |
| Percentage of LoanParticipationsSold | 100.0 | 0.0 |
| Period End | 2020-12-31 |
| Value | 11 |
| Percentage of LoansReceviableAmount | 100.0 |
| Period End | 2021-02-25 |
| Value | 45.0 |
| Percentage of NatureOfCommonOwnershipPercentage | 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 | 170 | 47 | 82 | -99.72 | 16 | 34 | 22 | 8.023 |
| Percentage of NetIncomeAvailableToCommonShareholders | 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 | 171 | 48 | 82 | -99.249 | 17 | 34 | 22 | 7.979 |
| Percentage of NetlossesIncome | 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 | 15000.0 | -1554000.0 | 0 | 60000.0 |
| Percentage of NoncashItems | 100.0 | 100.0 | 0.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 |
| Value | 0.141 | 4.049 |
| Percentage of NotesReceivableUnrealizedLosses | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 0.897 | -0.19 |
| Percentage of OutstandingLoanToRelatedParty | 100.0 | 100.0 |
| Period End | 2020-09-30 |
| Value | -0.19 |
| Percentage of OutstandingLoanToRelatedParty | 100.0 |
| Period End | 2021-02-25 |
| Value | 35442.0 |
| Percentage of OutstandingShareBasedAwards | 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 | -19628000.0 | -272000.0 | -2173000.0 | -505000.0 | 604000.0 | -335000.0 | -1577000.0 | -714000.0 | 375000.0 | -536000.0 | -2445000.0 | -1125000.0 |
| Percentage of PaymentOfEmploymentTaxesOnVestingOfRestrictedStock | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 |
| Value | 1088000.0 |
| Percentage of PreferredStockDividendsinDollar | 100.0 |
| Period End | 2021-01-15 |
| Value | 61 |
| Percentage of ProceedsFromDebtNetOfIssuanceCost | 100.0 |
| Period End | 2021-02-25 |
| Value | 55.0 |
| Percentage of RemainingPercentageOfNatureOfCommonOwnership | 100.0 |
| Period End | 2020-12-31 | 2020-03-31 | 2019-12-31 |
| Value | -1102000.0 | -244000.0 | -15736000.0 |
| Percentage of RepaymentOfLoanParticipationsSold | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 | 2019-09-30 |
| Value | -14101000.0 | -1532000.0 | -60444000.0 | -81102000.0 |
| Percentage of RepaymentsOfLoansReceivable | 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 |
| Value | 237 | 144 | 125 | 159 | 138 | 153 | 154 | 103 | 95 | 89 | 118 |
| Percentage of RevenueForServicesAndFees | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 |
| Value | -7.132 | 6.094 | 1.038 | 0.043 | 0.0 |
| Percentage of RevenueForServicesAndFees | -3.0 | 4.2 | 0.8 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 |
| Value | 8.886 | 15 | 0.518 | 0.251 | 0.0 | 0.0 | 0.0 | 0.061 | 0.061 | 0.006 | 0.808 |
| Percentage of RevenueForServicesAndFees | 3.7 | 10.8 | 0.4 | 0.2 | 0.0 | 0.0 | 0.0 | 0.1 | 0.1 | 0.0 | 0.7 |
| 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 |
| Value | 235 | 123 | 124 | 158 | 138 | 153 | 154 | 103 | 95 | 89 | 118 |
| Percentage of RevenueForServicesAndFees | 99.3 | 85.0 | 98.8 | 99.4 | 100.0 | 100.0 | 100.0 | 99.9 | 99.9 | 100.0 | 99.3 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 | 2019-09-30 |
| Value | 2.66 | 23 | 3.912 | 0.918 |
| Percentage of RevenuesFromSaleOfGoods | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 1.9 | 19 |
| Percentage of RevenuesFromSaleOfGoods | 71.4 | 82.1 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 |
| Value | 0.76 | 4.242 | 1.82 | 1.004 | 3.912 | 0.918 | 2.16 | 0.945 | 0.5 | 0.072 | 0.028 |
| Percentage of RevenuesFromSaleOfGoods | 28.6 | 17.9 | 0.0 | 0.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 237 | 144 | 125 | 103 | 113 | 139 |
| Percentage of RevenuesFromServicesAndFees | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 1.906 | 22 | 1.045 | 2.99 | 0.054 | 1.176 |
| Percentage of RevenuesSaleOfGoods | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 0.754 | 0.939 | 0.775 | 0.922 | 0.864 | 0.984 |
| Percentage of RevenuesSaleOfGoods | 39.6 | 4.1 | 74.2 | 30.8 | 1600.0 | 83.7 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 13 | 21 | 7.206 | -47.385 | 11 | 33 |
| Percentage of RevenuesServicesAndFees | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 |
| Value | 5.451 | 4.0 | 3.206 |
| Percentage of RevenuesServicesAndFees | 39.6 | 18.6 | 44.5 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 131 | 89 | 86 | 76 | 68 | 71 |
| Percentage of RevenuesServicesAndFees | 958.6 | 414.6 | 1205.4 | -162.4 | 606.0 | 212.5 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 20 | 20 | 20 | 22 | 22 | 24 |
| Percentage of RevenuesServicesAndFees | 149.9 | 96.2 | 286.7 | -48.0 | 204.8 | 73.5 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 |
| Value | 9.655 | 7.669 | 10 | 9.742 |
| Percentage of RevenuesServicesAndFees | 45.0 | 106.4 | 96.3 | 28.9 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 2.66 | 23 | 1.82 | 3.912 | 0.918 | 2.16 |
| Percentage of SaleOfGoods | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 |
| Value | 2292000.0 | -6318000.0 |
| Percentage of SegmentLoss | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 0 |
| Percentage of ServicesFees | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 |
| Value | -273000.0 | 2157000.0 | -335000.0 | 1577000.0 |
| Percentage of StockIsssueDuringPeriodValueESPPSharesIssuedAndVestingOfRestrictedStockNetOfSharesWithheldForEmployerTaxes | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 |
| Value | -273000.0 | 2157000.0 | -335000.0 | 1578000.0 |
| Percentage of StockIsssueDuringPeriodValueESPPSharesIssuedAndVestingOfRestrictedStockNetOfSharesWithheldForEmployerTaxes | 100.0 | 100.0 | 100.0 | 100.1 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 3.448 | 31 |
| Percentage of StockIssuedDuringPeriodPreferredStockIssued | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 3.448 | 31 |
| Percentage of StockIssuedDuringPeriodPreferredStockIssued | 100.0 | 100.0 |
| Period End | 2020-07-02 |
| Value | 9900000.0 |
| Percentage of StockOfRemainingValueDuringPeriod | 100.0 |
| Period End | 2020-10-28 | 2020-12-31 |
| Value | 2.698 | 0.897 |
| Percentage of SubsidiariesAmountValue | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 |
| Value | 31 | 114 | 40 | 5.595 |
| Percentage of TradingLossesIncomeAndFairValueAdjustmentOnLoans | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 140 | 31 | 114 | 34 | 40 | 5.595 |
| Percentage of TradinglossesIncomeAndFairValueAdjustmentsOnLoan | 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 | 2015-03-31 |
| Value | 3.77 | 3.919 | 4.024 | 4.024 | 3.815 | 3.31 | 3.344 | 3.377 | 2.736 | 2.093 | 2.146 | 2.16 | 2.174 | 2.172 | 1.554 | 1.522 | 1.566 | 1.465 | 0.111 | 0.112 | 0.092 |
| Percentage of AdjustmentForAmortization | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| Value | 749000.0 | 560000.0 | 864000.0 | 841000.0 | 520000.0 | 437000.0 | 584000.0 | 362000.0 | 1071000.0 | 371000.0 | 1192000.0 | 93000.0 | 85000.0 | 183000.0 | 862000.0 | 176000.0 | 221000.0 | 339000.0 | 761000.0 | 193000.0 |
| Percentage of AdvertisingExpense | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 585000.0 | 364000.0 | 392000.0 | 376000.0 |
| Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs | 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 | 62000.0 | 67000.0 | 72000.0 | 76000.0 | 82000.0 | 87000.0 | 93000.0 | 88000.0 |
| Percentage of AmortizationOfFinancingCostsAndDiscounts | 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 | 2016-03-31 | 2015-12-31 | 2015-09-30 |
| Value | 0.375 | 0.35 | 0.25 | 0.35 | 0.65 | 0.5 | 0.26 | 0.08 | 0.16 | 0.3 | 0.12 | 0.16 | 0.12 | 0.13 | 0.16 | 0.26 | 0.25 | 0.03 | 0 | 0.06 | 0.2 |
| Percentage of CommonStockDividendsPerShareCashPaid | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 |
| 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 |
| Value | 8.102 | 10 | 13 | 5.554 | 9.166 | 11 | 13 | 5.389 | 5.423 |
| Percentage of ContractWithCustomerLiabilityRevenueRecognized | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 0 |
| Percentage of DebtInstrumentIncreaseAccruedInterest | 0.0 |
| Period End | 2020-09-30 |
| Value | 0 |
| Percentage of DebtInstrumentPeriodicPayment | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | 0 | 0 | 566000.0 |
| Percentage of DebtInstrumentPeriodicPayment | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | 0 | 0 | 265000.0 |
| Percentage of DebtInstrumentPeriodicPayment | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 |
| Value | 0 | 0 | 4244000.0 | 0 | 0 |
| Percentage of DebtInstrumentPeriodicPayment | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2023-12-31 | 2019-09-30 |
| Value | -13000.0 | 0 |
| Percentage of DebtInstrumentPeriodicPayment | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | -15.379 | -0.339 | 0.0 | 148 |
| Percentage of DebtInstrumentPeriodicPaymentPrincipal | 100.0 | 100.0 | 0.0 | 100.0 |
| Period End | 2021-01-23 |
| Value | 400 |
| Percentage of DebtInstrumentPeriodicPaymentPrincipal | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2018-06-30 |
| Value | 0.195 | 0.068 | 0.07 | 1.478 | 0.246 | 11 | 2.491 |
| Percentage of DeferredRevenueRevenueRecognized1 | 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 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 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 | 834000.0 | 967000.0 | 899000.0 | 932000.0 | 1016000.0 | 1163000.0 | 1487000.0 | 1536000.0 | 1305000.0 | 1005000.0 | 1187000.0 | 1177000.0 | 1243000.0 | 696000.0 | 520000.0 | 531000.0 | 84000.0 | 203000.0 | 214000.0 | 213000.0 | 226000.0 | 195000.0 | 195000.0 | 187000.0 | 133000.0 | 131000.0 | 146000.0 | 320000.0 | 690000.0 | 707000.0 | 224000.0 | 201000.0 | 209000.0 | 201000.0 | 356000.0 | 186000.0 | 218000.0 | 221000.0 | 212000.0 | 205000.0 |
| Percentage of DepreciationAndAmortization | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 10 | 9.28 | 6.594 | 19 | 14 | 7.201 |
| Percentage of DividendsCommonStockCash | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 10 | 9.28 | 6.594 | 19 | 14 | 7.201 |
| Percentage of DividendsCommonStockCash | 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 | 1480000.0 | 1088000.0 | 1087000.0 | 1055000.0 |
| Percentage of DividendsPreferredStock | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 |
| Value | 1480000.0 | 1088000.0 | 1087000.0 |
| Percentage of DividendsPreferredStock | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | 1480000.0 | 1088000.0 | 1087000.0 | 1055000.0 |
| Percentage of DividendsPreferredStock | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | 1480000.0 | 1088000.0 | 1087000.0 | 1055000.0 |
| Percentage of DividendsPreferredStockStock | 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 | 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 | 904000.0 | 1112000.0 | 627000.0 | -1332000.0 | 256000.0 | -220000.0 | 14000.0 | 23000.0 | -64000.0 | -297000.0 | -185000.0 | -314000.0 | -1244000.0 | 1001000.0 | 267000.0 | 2012000.0 | -1742000.0 | -61000.0 | 59000.0 | 25000.0 | -119000.0 | -17000.0 | 314000.0 | 344000.0 | 127000.0 | -554000.0 | -153000.0 | 420000.0 | -282000.0 | 144000.0 | -231000.0 | 3000.0 | -14000.0 | 2000.0 | -13000.0 |
| Percentage of EffectOfExchangeRateOnCashAndCashEquivalents | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2017-12-22 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 |
| Value | -8.4 | 29.158 | -0.032 | 0.274 | -0.084 | 0.004 | 0.01 | 0.28 | -0.039 | 0.03 | 0.049 | 0.17 | 0.21 | 0.21 | 0.216 | 0.206 | 0.383 | -0.039 | 0.319 | -0.038 | 0.108 | 0 | -0.34 | 0.68 | 0 | -0.68 | 0.34 | 0 | 0 | 0 | 0.34 | 0 | 0.68 |
| Percentage of EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 0.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 | 2019-09-30 |
| Value | 0.158 | 0.14 | -0.649 | 3.029 |
| Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings | 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 | 6.956 | -8.852 | 12 | -15.135 | -5.524 | -4.552 | 5.285 | -0.018 |
| Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings | 4402.5 | -6322.9 | 0.0 | 0.0 | 851.2 | -150.3 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 | 2019-09-30 |
| Value | 918000.0 | 672000.0 | 0 | 1146000.0 |
| Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInOtherComprehensiveIncome | 100.0 | 100.0 | 0.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 | 2019-09-30 |
| Value | 238000.0 | 111000.0 | 221000.0 | 171000.0 |
| Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInOtherComprehensiveIncome | 25.9 | 16.5 | 0.0 | 14.9 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 | 2019-09-30 |
| Value | 45 | 18 | 8.476 | -10.511 |
| Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchasesSalesIssuancesSettlements | 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 | 49 | 3.984 | 0.0 | 1.0 | 67 | 22 | 1.496 | -0.045 |
| Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchasesSalesIssuancesSettlements | 108.7 | 22.1 | 0.0 | 0.0 | 790.8 | -216.6 | 0.0 | 0.0 |
| Period End | 2020-12-31 |
| Value | -9.107 |
| Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet | 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 |
| Value | -1052000.0 | -97000.0 | -438000.0 | 949000.0 | -359000.0 | 446000.0 | -139000.0 | -186000.0 | 451000.0 | -51000.0 | 756000.0 |
| Percentage of ForeignCurrencyTransactionGainLossRealized | 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 | 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 | -142000.0 | 529000.0 | 252000.0 | -179000.0 | 86000.0 | 331000.0 | -209000.0 | -130000.0 | 564000.0 | -230000.0 | 534000.0 | 48000.0 | -253000.0 | 167000.0 | -312000.0 | 1167000.0 | -333000.0 | 12000.0 | 368000.0 | 34000.0 | -39000.0 | -59000.0 | -122000.0 | -168000.0 | 212000.0 | -515000.0 | 117000.0 | 108000.0 | 64000.0 | 50000.0 | 453000.0 | -341000.0 | -64000.0 | -71000.0 | -33000.0 | 96000.0 | 22000.0 | -27000.0 |
| Percentage of ForeignCurrencyTransactionGainLossUnrealized | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | -478000.0 | 409000.0 | -318000.0 | 2618000.0 | 1113000.0 | -1400000.0 |
| Percentage of GainLossOnSaleOfEquityInvestments | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 0 | 1557000.0 |
| Percentage of ImpairmentOfLongLivedAssetsHeldForUse | 0.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 0 | 140000.0 |
| Percentage of ImpairmentOfLongLivedAssetsHeldForUse | 0.0 | 9.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | -500000.0 | 1417000.0 |
| Percentage of ImpairmentOfLongLivedAssetsHeldForUse | 0.0 | 91.0 |
| Period End | 2020-09-30 | 2019-09-30 |
| Value | 1.75 | 1.21 |
| Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare | 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 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 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 | -478000.0 | 409000.0 | -318000.0 | -236000.0 | 2618000.0 | 1113000.0 | -1400000.0 | -3762000.0 | 2937000.0 | 828000.0 | 4893000.0 | -672000.0 | -280000.0 | -157000.0 | 0 | 0 | 0 | -6000.0 | 0 | -15000.0 | 0 | -165000.0 | 165000.0 | -40000.0 | -80000.0 | 153000.0 | -174000.0 | -416000.0 | 68000.0 | -372000.0 | -401000.0 | -455000.0 |
| Percentage of IncomeLossFromEquityMethodInvestments | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 0.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | -478000.0 | 409000.0 | -318000.0 | 2618000.0 | 1113000.0 | -1400000.0 |
| Percentage of IncomeLossFromEquityMethodInvestments | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 |
| Value | -0.208 | -0.208 | -0.589 | -19.935 | -0.6 | -0.421 | -0.433 | -0.933 | 0.0 |
| Percentage of IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 |
| Value | 48 | 83 | 34 | 22 |
| Percentage of IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions | -23259.1 | -40307.7 | -5717.0 | -5262.9 |
| Period End | 2020-12-31 |
| Value | -0.63 |
| Percentage of IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance | 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 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 41 | -11.035 | 22 | -22.097 | 1.08 | 30 | 2.394 | -1.251 | -6.552 | 4.791 | 15 | -10.049 | 8.223 | -15.849 | -11.621 | -11.127 | 20 | 9.173 | 0.645 | -6.643 | -1.082 | -3.847 | 7.811 | 1.407 | 1.051 | 0.338 | -0.061 | -2.47 | 2.336 | 1.494 | -7.445 | -0.356 | 3.738 | 1.136 | -5.119 | 1.886 | -5.182 | 10 | 3.129 | -5.078 | 1.817 | -4.192 |
| Percentage of IncreaseDecreaseInAccountsPayableAndAccruedLiabilities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 |
| Value | -1914000.0 | -452000.0 | -2596000.0 | 288000.0 | -628000.0 | -395000.0 | 81000.0 | 378000.0 | 634000.0 | -877000.0 | -110000.0 | -315000.0 | -79000.0 |
| Percentage of IncreaseDecreaseInDeferredRevenue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| 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 |
| Value | -2.33 | 3.311 | -3.652 | -0.752 | 0.207 | 1.12 | 2.218 | 1.236 | -9.192 | 7.849 | -2.889 | -0.473 | -0.487 | -1.02 | 2.425 | 10 | 2.278 | -1.447 | 0.379 | 1.556 | -3.294 | 2.606 | 0.552 | 0.758 | -0.279 | -0.177 | 0.111 | 0.177 | -0.018 | 0.064 | -0.419 | 0.373 | 0.0 | 0.0 | 0.0 | 0.0 |
| Percentage of IncreaseDecreaseInDueFromRelatedParties | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 2013-12-31 | 2013-09-30 |
| Value | -38.019 | 38 | -4.495 | -27.522 | 12 | -13.662 | 6.806 | -1.675 | -22.049 | 42 | -2.153 | -8.555 | -0.022 | 5.025 | 1.862 | 0.813 | 0.476 | -5.562 | 4.98 | 0.239 | -5.768 | -1.576 | 7.101 | 0.21 | -2.036 | -3.707 | 0.0 | 0.0 |
| Percentage of IncreaseDecreaseInFinancialInstrumentsSoldNotYetPurchased | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 |
| Value | 26 | 9.501 | -18.21 | 12 | 3.973 | 1.454 | -6.827 | 15 | 17 | -19.649 | 12 | -16.417 | -9.899 | -0.15 |
| Percentage of IncreaseDecreaseInPayablesToBrokerDealers | 100.0 | 100.0 | 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 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | -7.93 | -16.2 | -17.444 | 37 | -19.207 | -35.881 | 41 | 3.706 | 4.977 | 3.31 | 0.074 | 16 | 17 | -0.534 | -14.746 | -0.242 | -2.252 | -9.056 | 5.586 | 2.06 | 1.109 | -1.423 | 1.509 | -0.095 | -0.616 | 0.216 | 0.075 | 0.384 | -0.547 | 0.396 | -0.071 | 0.055 | 0.347 | -0.52 | -0.165 | 0.371 | -1.6 | 0.119 | 0.574 | -0.186 | -2.55 | 0.865 |
| 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 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2013-12-31 | 2013-09-30 |
| Value | 89 | -109.941 | 112 | -140.168 | 94 | -39.714 | -67.321 | -104.104 | -110.949 | 28 | 152 | 54 | 82 | -178.132 | 0.067 | 7.995 | 3.866 | 3.068 | -7.341 | 1.717 | 13 | 0.0 | 0.0 |
| Percentage of IncreaseDecreaseInSecuritiesBorrowed | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 |
| Value | 92 | -111.905 | 108 | -139.636 | 95 | -44.162 | -65.724 | -105.689 | -104.886 | 23 | 157 | 51 | 75 | -183.79 |
| Percentage of IncreaseDecreaseInSecuritiesLoanedTransactions | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 30 | 26 | 24 | 23 | 25 | 16 |
| Percentage of InterestIncomeSecuritiesTaxable | 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 | 27000.0 | 67000.0 | 248000.0 | 361000.0 |
| Percentage of InvestmentIncomeInterest | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 |
| Value | -67.153 | 63 | -18.605 | 21 | -66.575 | 113 | -112.723 | -9.348 | -54.044 | 42 | 94 | -54.51 | 31 | -3.262 | 32 | -42.576 | 87 | -21.588 | 21 | -3.251 |
| Percentage of NetCashProvidedByUsedInContinuingOperations | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | -1344000.0 | -526000.0 | -515000.0 | -357000.0 | 521000.0 | -167000.0 |
| Percentage of OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2019-09-30 |
| Value | 31 | 40 |
| Percentage of OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | 1.018 | 9.813 | 0.86 | 3.74 | 0.911 | 1.805 |
| Percentage of OtherCostAndExpenseOperating | 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 | 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 | 3.909 | 5.958 | 4.116 | 2.827 | -2.674 | 11 | 3.88 | -0.736 | -2.684 | 0.486 | -1.684 | -0.186 | -0.137 | -0.153 | -0.151 | -0.015 | 0.011 | -0.093 | -0.023 | -0.031 | -0.045 | -0.045 | -0.044 | -0.029 | 0.0 | 0.0 | 0.0 | 0.0 | -0.01 | 0.007 | -0.074 | 0.077 | 0.065 | -1.728 | 0.152 | 0.428 | -0.123 |
| Percentage of OtherNoncashIncomeExpense | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 0.451 | 0.382 | 0.222 | 0.175 | 0.363 | 0.411 | 0.277 | 0.169 | 0.375 | 0.304 | 0.368 | 0.175 | 0.033 | 3.498 | 6.866 | 0.402 | 1.582 | 0.49 | 0.535 | 0.425 | 0.411 | 0.68 | 0.714 | 0.402 | 0.312 | 0.299 | 0.948 | 0.333 | 0.333 | 0.528 | 0.745 | 0.291 | 0.431 | 0.505 | 0.623 | 0.369 | 0.396 | 2.145 | 0.655 | 0.738 | 0.632 | 0.513 |
| Percentage of OtherOperatingActivitiesCashFlowStatement | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2018-12-31 | 2018-09-30 | 2017-12-31 | 2017-09-30 |
| Value | 0 | 0 | 4000000.0 | 0 | 0 |
| Percentage of OtherPaymentsToAcquireBusinesses | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2016-12-31 | 2014-12-31 |
| Value | 81000.0 | 189000.0 | 315000.0 | 316000.0 | 323000.0 | 779000.0 | 2411000.0 | 636000.0 | 1713000.0 | 504000.0 | 1229000.0 | 1221000.0 | 434000.0 | 155000.0 |
| Percentage of PaymentsForRestructuring | 100.0 | 100.0 | 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 |
| Value | 598000.0 | 1000.0 | 36000.0 | 2724000.0 | -787000.0 | 2173000.0 | 1894000.0 | 145000.0 | 904000.0 | 1420000.0 | 4860000.0 | 76000.0 | 2196000.0 | -435000.0 |
| Percentage of PaymentsOfDebtIssuanceCosts | 100.0 | 100.0 | 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 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 0.813 | 0.87 | 0.82 | 1.323 | 0.863 | 0.239 | 0.582 | 0.274 | 0.152 | 0.133 | 0.665 | 0.117 | 8.383 | 1.232 | 1.075 | 0.571 | 0.327 | 0.239 | 0.776 | 0.665 | 2.245 | 0.376 | 1.12 | 0.301 | 0.3 | 0.245 | 0.706 | 0.543 | 0.342 | 0.346 | 0.63 | 0.612 | 0.392 | 0.25 | 0.785 | 1.039 | 0.339 | 1.35 | 1.183 | 0.429 | 0.535 | 0.288 |
| Percentage of PaymentsOfDividendsMinorityInterest | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2020-03-31 |
| Value | 1480000.0 | 1055000.0 |
| Percentage of PaymentsOfDividendsPreferredStockAndPreferenceStock | 100.0 | 100.0 |
| Period End | 2021-01-25 | 2020-02-12 |
| Value | 4.254 | 3.037 |
| Percentage of PaymentsOfFinancingCosts | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 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 | 2014-12-31 | 2014-09-30 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2011-06-30 | 2011-03-31 | 2010-12-31 | 2010-09-30 |
| Value | 7.5 | 0.0 | 0.0 | 8.208 | 14 | 10 | 9.784 | 3.281 | 0.0 | 3.575 | 0.659 | 1.015 | 0.0 | 0.0 | 0.006 | 0.0 | 0.015 | 0.0 | 0.0 | 0.0 | 0.04 | 0.08 | 0.871 | 0.175 | 0.11 | 0.046 | -0.318 | -0.508 |
| Percentage of PaymentsToAcquireEquityMethodInvestments | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 38 | 16 | 36 | 115 | -6.884 | 125 | 204 | 20 | 3.683 |
| Percentage of PaymentsToAcquireLoansReceivable | 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 | 528000.0 | 666000.0 | 413000.0 | 438000.0 | 576000.0 | 371000.0 | 768000.0 | 1746000.0 |
| Percentage of PaymentsToAcquireOtherPropertyPlantAndEquipment | 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 | 429.68 | 429.69 | 429.69 |
| Percentage of PreferredStockDividendsPerShareCashPaid | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 |
| Value | 0.42969 |
| Percentage of PreferredStockDividendsPerShareCashPaid | 0.1 |
| Period End | 2020-12-31 | 2020-03-31 |
| Value | 3.448 | 4.63 |
| Percentage of ProceedsFromIssuanceOfPreferredStockAndPreferenceStock | 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 |
| Value | 15 | 0.339 | 0.0 | 171 | 37 | 120 | 118 | 4.987 | 3.707 | 123 | 124 | 7.267 | 90 | 31 |
| Percentage of ProceedsFromIssuanceOfSeniorLongTermDebt | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2021-01-25 | 2020-02-12 |
| Value | 225 | 129 |
| Percentage of ProceedsFromNotesPayable | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-03-31 |
| Value | 0 | -1829000.0 |
| Percentage of ProceedsFromRepaymentsOfOtherLongTermDebt | 0.0 | 100.0 |
| Period End | 2020-12-31 | 2020-03-31 |
| Value | 0 | 1800000.0 |
| Percentage of ProceedsFromSaleOfLoansReceivable | 0.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 |
| Value | 0 | 0 | 0 | 1000.0 | 9000.0 | 1000.0 | 491000.0 | 12000.0 |
| Percentage of ProceedsFromSaleOfOtherPropertyPlantAndEquipment | 0.0 | 0.0 | 0.0 | 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 | 947000.0 | 357000.0 | 940000.0 | 724000.0 | 480000.0 | 615000.0 | 834000.0 | 233000.0 | 468000.0 | 343000.0 | 343000.0 | 305000.0 | 239000.0 | 123000.0 | 379000.0 | 325000.0 | 888000.0 | 428000.0 | 55000.0 | -20000.0 | 352000.0 | 111000.0 | 195000.0 | 60000.0 | 366000.0 | 133000.0 | 33000.0 | 0 | -20000.0 | 13000.0 | 13000.0 | 0 | 101000.0 | 7000.0 | 0 | 0 | 424000.0 | 0 | 0 |
| Percentage of ProvisionForDoubtfulAccounts | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 0.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 | 2019-09-30 |
| Value | 947000.0 | 356000.0 | 445000.0 | 615000.0 |
| Percentage of ProvisionForDoubtfulAccounts | 100.0 | 99.7 | 92.7 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 |
| Value | 52 | 4.809 | 4.81 | 4.81 | 4.81 | 9.619 |
| Percentage of RepaymentsOfBankDebt | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-03-31 | 2018-12-31 | 2018-09-30 | 2017-12-31 | 2017-09-30 |
| Value | 0.0 | 37 | 0.0 | 105 | 0.0 | 20 |
| Percentage of RepaymentsOfLongTermLinesOfCredit | 0.0 | 100.0 | 0.0 | 100.0 | 0.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2012-03-31 | 2011-12-31 | 2011-09-30 | 2010-12-31 |
| Value | 0.0 | 0.0 | 0.0 | 0.357 | 0.121 | 0.0 | 0.0 | 0.357 | 0.122 | 51 | 0.0 | 0.357 | 0.122 | 8.214 | 0.0 | 0.0 | -0.639 | 0.925 | 0.289 | 0.565 | 0.761 | 1.17 | 0.096 | 0.064 | 1.872 | 0.106 | 7.48 | 0.306 | -1.699 |
| Percentage of RepaymentsOfNotesPayable | 0.0 | 0.0 | 0.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 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 | 2014-12-31 | 2014-09-30 | 2013-12-31 | 2013-09-30 |
| Value | 0.0 | 1.557 | 0.0 | 0.0 | 1.552 | 0.147 | 6.259 | 0.428 | 1.602 | 0.217 | 0.89 | 4.896 | 6.214 | 0.374 | 0.302 | 3.585 | 0.0 | 2.548 | 0.0 | 0.0 |
| Percentage of RestructuringCharges | 0.0 | 100.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 0.0 | 0.14 |
| Percentage of RestructuringCharges | 0.0 | 9.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 0.0 | 0.14 |
| Percentage of RestructuringCharges | 0.0 | 9.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 |
| Value | -0.5 | 1.417 | 0.0 | 0.0 | 0.025 |
| Percentage of RestructuringCharges | 0.0 | 91.0 | 0.0 | 0.0 | 1.6 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 |
| Value | -0.5 | 1.417 | 0.0 | 0.0 | 0.025 | -0.029 | 5.921 | 0.428 | 1.774 | 0.255 |
| Percentage of RestructuringCharges | 0.0 | 91.0 | 0.0 | 0.0 | 1.6 | -19.7 | 94.6 | 100.0 | 110.7 | 117.5 |
| Period End | 2021-02-17 |
| Value | 36553.0 |
| Percentage of StockIssuedDuringPeriodValueRestrictedStockAwardGross | 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 |
| Value | 86 | -10.569 | 3.711 | -24.068 | 0.0 | -1.021 | -0.602 | -2.65 | -1.365 | 0.0 | -17.338 |
| Percentage of StockRepurchasedAndRetiredDuringPeriodValue | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 |
| Value | 86 | -10.569 | 3.711 | -24.068 | 0.0 | -1.021 | -0.602 | -2.65 | -1.365 | 0.0 | -17.338 |
| Percentage of StockRepurchasedAndRetiredDuringPeriodValue | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 100.0 |
| Period End | 2020-07-02 | 2020-07-01 | 2020-01-02 |
| Value | 450000.0 | 900000.0 | 450000.0 |
| Percentage of StockRepurchasedDuringPeriodShares | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-07-01 | 2020-07-02 | 2020-01-02 |
| Value | 10 | 19 | 9.9 | 9.9 |
| Percentage of StockRepurchasedDuringPeriodValue | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-07-02 |
| Value | 19 |
| Percentage of StockRepurchasedDuringPeriodValue | 200.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 |
| Value | 0.2 | 0.9 | 1.413 | 11 | 27 |
| Percentage of AdvancesAgainstCustomerContracts | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 3.25 |
| Percentage of ClassOfWarrantOrRightExercisesPriceOfWarrantsOrRights1 | 100.0 |
| Period End | 2020-10-28 |
| Value | 3367.0 |
| Percentage of ConversionOnNotesReceivable | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 2333000.0 | 6246000.0 |
| Percentage of DeductibleGoodwillAndOtherIntangibles | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 |
| Value | 43 | 0.222 | 0.702 |
| Percentage of DeferredTaxLiabilitiesDeferredRevenue | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 |
| Value | 112000.0 | -143000.0 | 421000.0 | 73000.0 | 1291000.0 |
| Percentage of DeferredTaxLiabilitiesDepreciation | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 34 |
| Percentage of DeferredTaxLiabilitiesNet | 100.0 |
| Period End | 2020-12-31 |
| Value | 434000.0 |
| Percentage of DeferredTaxLiabilitiesShareBasedPayments | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 1.7188 | 0.11458 |
| Percentage of DepositoryPerShare | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 0.29193 |
| Percentage of DepositoryPerShare | 17.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.3 | 0.175 |
| Percentage of DividendsPayableRegularDividendAmount | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.25 | 0.08 |
| Percentage of DividendsPayableRegularDividendAmount | 83.3 | 45.7 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.25 | 0.08 |
| Percentage of DividendsPayableRegularDividendAmount | 83.3 | 45.7 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.175 | 0.08 |
| Percentage of DividendsPayableRegularDividendAmount | 58.3 | 45.7 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.175 | 0.08 |
| Percentage of DividendsPayableRegularDividendAmount | 58.3 | 45.7 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.375 | 0.175 |
| Percentage of DividendsPayableRegularDividendAmount | 125.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.05 | 0.325 |
| Percentage of DividendsPayableSpecialDividendAmount | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0 | 0.18 |
| Percentage of DividendsPayableSpecialDividendAmount | 0.0 | 55.4 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.1 | 0 |
| Percentage of DividendsPayableSpecialDividendAmount | 200.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.475 | 0.08 |
| Percentage of DividendsPayableSpecialDividendAmount | 950.0 | 24.6 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.325 | 0.22 |
| Percentage of DividendsPayableSpecialDividendAmount | 650.0 | 67.7 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.18 | 0.04 |
| Percentage of DividendsPayableSpecialDividendAmount | 360.0 | 12.3 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0 | 0.08 |
| Percentage of DividendsPayableSpecialDividendAmount | 0.0 | 24.6 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0 | 0.475 |
| Percentage of DividendsPayableSpecialDividendAmount | 0.0 | 146.2 |
| Period End | 2020-12-31 |
| Value | 13 |
| Percentage of DueToClearingBrokers | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 48 | 44 | 41 | 37 | 33 | 29 | 26 | 33 | 19 |
| Percentage of IndefiniteLivedTradeNamesAccumulatedAmortization | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 239 | 239 | 241 | 250 | 254 | 109 | 109 | 254 | 111 |
| Percentage of IndefiniteLivedTradeNamesGross | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 125 | 125 | 125 | 134 | 138 | 2.24 | 2.24 | 138 | 2.24 |
| Percentage of IndefiniteLivedTradeNamesGross | 52.4 | 52.4 | 52.1 | 53.7 | 54.5 | 2.1 | 2.1 | 54.5 | 2.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 74923.0 | 27617.0 |
| Percentage of InterestsValue | 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 | 2015-12-31 |
| Value | 10 | 4.247 | 4.879 | 9.607 | 8.043 | 14 | 17 | 11 | 26 | 16 | 4.226 | 7.761 | 4.199 | 5.074 | 4.882 | 0.807 | 0.576 | 0.709 |
| Percentage of InvestmentBankingFeesCommissionsAndOtherReceivable | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 26948.0 |
| Percentage of InvestmentSecurities | 100.0 |
| Period End | 2020-09-30 |
| Value | 80 |
| Percentage of LoanAmount | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 17 | 12 |
| Percentage of LoanParticipationsSold2 | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 56 |
| Percentage of LoanReceivable | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 405 | 355 | 336 | 32 |
| Percentage of LoansReceivableFairValue | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 4700000.0 | 4462000.0 | 4351000.0 | 4616000.0 |
| Percentage of MandatorilyRedeemableNoncontrollingInterests | 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 | 48 | 109 | 119 | 31 | 13 | 18 |
| Percentage of NetDeferredTaxAssets | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 30 | -31.522 |
| Percentage of NetDeferredTaxliabilitiesAssets | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 |
| Value | 11 | 5.087 | 4.991 | 333 | 32 |
| Percentage of NetOfUnamortizedCostsOriginationFeesPremiumsAndDiscounts | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-10-28 |
| Value | 3367.0 |
| Percentage of NotesReceivableFromRelatedParty | 100.0 |
| Period End | 2020-12-31 |
| Value | 12 |
| Percentage of OperatingLeasesImputedInterest | 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 | 2017-12-31 | 2016-12-31 |
| Value | 20.3 | 19.4 | 0.19 | 0.198 | 0.066 | 0.041 | 0.038 | 0.031 | 0.03 | 0.064 | 0.052 |
| Percentage of PercentageOfAssetsMeasuredAtFairValue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 539 | 446 | 433 | 152 |
| Percentage of SecurityOwnedNotReadilyMarketableFairValue2 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 60 |
| Percentage of TotalOperatingLeaseLiabilities | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 |
| Value | 63 | 0.372 | 0.012 |
| Percentage of VariableInterestEntityEntityDueFromRelatedPartyAmount | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 |
| Value | 23 | 20 | 12 |
| Percentage of VariableInterestEntityEntityPartnershipInvestmentsAmount | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 77000.0 |
| Percentage of unrecognizedTaxBenefitsMayDecrease | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 140 | 134 |
| Percentage of AlternativeExcessNetCapital | 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 | 4.299 | 3.444 | 4.263 | 4.975 | 4.708 | 5.447 | 3.599 | 4.44 |
| Percentage of AlternativeExcessNetCapital | 3.1 | 2.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 5.959 | 3.504 |
| Percentage of AlternativeExcessNetCapital | 4.3 | 2.6 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 |
| Value | 0.699 | 0.646 | 0.66 | 0.594 | 0.479 |
| Percentage of AlternativeExcessNetCapital | 0.5 | 0.5 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 146 | 137 |
| Percentage of NetCapital | 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 | 4.998 | 4.09 | 4.923 | 5.569 | 5.187 | 5.914 | 4.096 | 4.972 |
| Percentage of NetCapital | 3.4 | 3.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 |
| Value | 49 | 48 | 45 | 48 | 48 | 48 | 57 | 44 | 42 | 39 | 33 | 26 | 20 | 20 | 19 | 18 | 19 | 8.014 | 9.561 | 10 | 24 | 15 | 10 | 11 | 14 | 10 | 9.133 | 10 | 9.386 | 9.421 | 16 | 6.456 | 6.24 | 7.906 |
| Percentage of AccountsReceivableGross | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2011-12-31 |
| Value | 33 | 38 | 36 | 34 | 36 | 29 | 27 | 20 | 12 | 22 | 18 | 13 | 15 | 14 | 13 | 14 | 16 | 15 | 8.083 | 6.948 | 8.417 | 9.793 | 22 | 12 | 7.797 | 8.387 | 12 | 9.192 | 8.402 | 8.541 | 8.394 | 9.169 | 16 | 6.305 | 6.009 | 7.829 |
| Percentage of AccountsReceivableGrossCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2018-12-31 | 2017-12-31 |
| Value | 3114000.0 | 2752000.0 | 2760000.0 | 1514000.0 | 1461000.0 | 1360000.0 | 696000.0 | 800000.0 |
| Percentage of AllowanceForDoubtfulAccountsReceivable | 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 | 2011-12-31 |
| Value | 3114000.0 | 2752000.0 | 2760000.0 | 2238000.0 | 1514000.0 | 1461000.0 | 1360000.0 | 766000.0 | 696000.0 | 824000.0 | 796000.0 | 661000.0 | 800000.0 | 628000.0 | 599000.0 | 556000.0 | 255000.0 | 178000.0 | 86000.0 | 69000.0 | 89000.0 | 795000.0 | 973000.0 | 788000.0 | 728000.0 | 415000.0 | 331000.0 | 275000.0 | 275000.0 | 371000.0 | 371000.0 | 371000.0 | 371000.0 | 308000.0 | 424000.0 | 424000.0 |
| 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 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 |
| Value | 390 | 344 | 325 |
| Percentage of AssetsFairValueDisclosure | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 |
| Value | 149 | 102 | 107 | 95 | 109 |
| Percentage of AssetsFairValueDisclosure | 38.2 | 29.7 | 33.1 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 |
| Value | 539 | 446 | 433 | 86 | 74 | 59 | 58 | 98 |
| Percentage of AssetsFairValueDisclosure | 138.2 | 129.7 | 133.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 |
| Value | 290 | 233 | 139 | 243 |
| Percentage of AssetsFairValueDisclosure | 84.3 | 71.8 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 |
| Value | 9.513 | 8.143 | 23 | 27 |
| Percentage of AssetsFairValueDisclosure | 2.8 | 2.5 | 0.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 |
| Value | 446 | 433 | 421 | 152 |
| Percentage of AssetsFairValueDisclosure | 129.7 | 133.1 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 521 | 243 |
| Percentage of AssetsFairValueDisclosure | 133.4 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 5.108 | 27 |
| Percentage of AssetsFairValueDisclosure | 1.3 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 539 | 152 |
| Percentage of AssetsFairValueDisclosure | 138.2 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2017-12-31 |
| Value | 803 | 724 | 614 | 451 | 326 | 270 | 288 | 273 | 145 |
| Percentage of AssetsFairValueDisclosure | 233.4 | 222.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 1066 | 423 |
| Percentage of AssetsFairValueDisclosure | 272.9 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2016-12-31 | 2013-09-30 |
| Value | 0.471 | 0.471 | 0.471 | 0.471 | 0.471 | 0.47 | 0.469 | 0.469 | 8.904 | 19 | 8.759 | 5.144 | 1.44 | 7.132 |
| Percentage of CashCollateralForBorrowedSecurities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 37 | 0.714 | 0.714 | 38 |
| Percentage of ConvertibleNotesPayable | 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 | 2016-12-31 |
| Value | 880 | 864 | 864 | 864 | 696 | 711 | 591 | 472 | 467 | 463 | 340 | 215 | 208 | 28 |
| Percentage of DebtInstrumentCarryingAmount | 100.0 | 100.0 | 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 |
| Value | 54 | 39 | 38 |
| Percentage of DebtInstrumentCarryingAmount | 6.2 | 4.5 | 4.5 |
| 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 |
| Value | 128 | 125 | 125 | 125 | 117 | 110 | 110 | 108 | 108 | 107 | 100 | 93 | 92 |
| Percentage of DebtInstrumentCarryingAmount | 14.6 | 14.5 | 14.5 | 14.5 | 16.9 | 15.5 | 18.6 | 23.0 | 23.3 | 23.2 | 29.6 | 43.6 | 44.4 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 |
| Value | 122 | 122 | 122 | 122 | 120 | 112 | 110 | 100 | 100 | 100 | 96 | 85 | 80 |
| Percentage of DebtInstrumentCarryingAmount | 13.9 | 14.2 | 14.2 | 14.2 | 17.2 | 15.8 | 18.7 | 21.3 | 21.5 | 21.7 | 28.5 | 39.9 | 38.7 |
| 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 |
| Value | 137 | 127 | 127 | 127 | 122 | 116 | 114 | 112 | 111 | 109 | 101 |
| Percentage of DebtInstrumentCarryingAmount | 15.6 | 14.8 | 14.7 | 14.7 | 17.5 | 16.4 | 19.4 | 23.8 | 23.9 | 23.6 | 29.9 |
| 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 |
| Value | 115 | 113 | 113 | 113 | 105 | 105 | 103 | 100 | 100 | 100 |
| Percentage of DebtInstrumentCarryingAmount | 13.1 | 13.1 | 13.1 | 13.1 | 15.2 | 14.8 | 17.5 | 21.4 | 21.4 | 21.6 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 |
| Value | 134 | 134 | 134 | 134 | 124 |
| Percentage of DebtInstrumentCarryingAmount | 15.3 | 15.6 | 15.6 | 15.6 | 17.8 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 111 | 110 | 110 | 106 |
| Percentage of DebtInstrumentCarryingAmount | 12.6 | 12.8 | 12.8 | 15.3 |
| Period End | 2021-03-01 |
| Value | 128 |
| Percentage of DebtInstrumentCarryingAmount | 0.0 |
| Period End | 2021-01-25 |
| Value | 230 |
| Percentage of DebtInstrumentCarryingAmount | 0.0 |
| Period End | 2020-12-31 |
| Value | 150 |
| Percentage of DebtInstrumentCarryingAmount | 17.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 74 | 52 |
| Percentage of DebtInstrumentFaceAmount | 100.0 | 100.0 |
| Period End | 2023-12-19 |
| Value | 80 |
| Percentage of DebtInstrumentFaceAmount | 0.0 |
| Period End | 2020-12-31 |
| Value | 12.5 |
| Percentage of DebtInstrumentInterestRateEffectivePercentage | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2018-12-31 |
| Value | 9.557 | 10 | 10 | 8.875 | 10 | 7.464 |
| Percentage of DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet | 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 | 2018-12-31 |
| Value | 6.95 | 6.94 | 0.0694 | 0.0694 | 0.0705 | 0.0708 | 0.0728 |
| Percentage of DebtWeightedAverageInterestRate | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 10 |
| Percentage of DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 |
| Value | 68 | 70 | 67 |
| Percentage of DeferredIncome | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 |
| Value | 51 | 9.156 | 1.198 | 0.119 | 5.43 |
| Percentage of DeferredIncomeTaxLiabilities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 4.098 | 14 | 14 | 31 |
| Percentage of DeferredIncomeTaxesAndOtherAssetsCurrent | 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 | 2018-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 68 | 70 | 71 | 73 | 67 | 68 | 69 | 1.076 | 0.624 |
| Percentage of DeferredRevenue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2025-12-31 |
| Value | 3.326 |
| Percentage of DeferredRevenue | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 | 2017-12-31 | 2016-12-31 |
| Value | 61 | 61 | 61 | 2.582 | 3.6 |
| Percentage of DeferredTaxAssetsCapitalLossCarryforwards | 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 | 1190000.0 | 1190000.0 | 1120000.0 | 1109000.0 | 1173000.0 | 768000.0 |
| Percentage of DeferredTaxAssetsEquityMethodInvestments | 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 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 |
| Value | 99 | 118 | 121 | 31 | 18 | 18 | 25 | 13 | 13 | 12 | 13 | 13 | 12 | 13 | 15 | 14 | 14 |
| Percentage of DeferredTaxAssetsGross | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 |
| Value | 33 | 45 | 45 | 17 | 7.711 | 4.92 | 8.22 | 9.429 | 8.687 | 8.665 | 8.063 | 7.175 | 5.418 | 5.773 | 9.313 | 8.83 | 9.394 |
| 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 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2018-12-31 | 2016-12-31 |
| Value | 237000.0 | 123000.0 | 994000.0 |
| Percentage of DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal | 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 | 1558000.0 | 1558000.0 | 1848000.0 | 290000.0 | 1855000.0 | 1427000.0 |
| Percentage of DeferredTaxAssetsTaxCreditCarryforwards | 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 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 |
| Value | 2066000.0 | 1793000.0 | 4182000.0 | 3549000.0 | 2459000.0 | 1177000.0 | 3210000.0 | 971000.0 | 1852000.0 | 1128000.0 | 1532000.0 | 1877000.0 | 2406000.0 | 2828000.0 | 1447000.0 | 1381000.0 | 934000.0 |
| Percentage of DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 4902000.0 |
| Percentage of DeferredTaxLiabilitiesOther | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.35 | 0.5 |
| Percentage of DividendsPayableAmountPerShare | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.25 | 0.26 |
| Percentage of DividendsPayableAmountPerShare | 71.4 | 52.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.35 | 0.08 |
| Percentage of DividendsPayableAmountPerShare | 100.0 | 16.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.65 | 0.16 |
| Percentage of DividendsPayableAmountPerShare | 185.7 | 32.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.5 | 0.3 |
| Percentage of DividendsPayableAmountPerShare | 142.9 | 60.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.26 | 0.12 |
| Percentage of DividendsPayableAmountPerShare | 74.3 | 24.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.08 | 0.16 |
| Percentage of DividendsPayableAmountPerShare | 22.9 | 32.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 0.375 | 0.65 |
| Percentage of DividendsPayableAmountPerShare | 107.1 | 130.0 |
| Period End | 2021-02-25 | 2019-10-07 |
| Value | 3.0 | 0.175 |
| Percentage of DividendsPayableAmountPerShare | 0.0 | 0.0 |
| Period End | 2021-02-25 | 2019-10-07 |
| Value | 0.5 | 0.08 |
| Percentage of DividendsPayableAmountPerShare | 0.0 | 0.0 |
| Period End | 2020-10-28 |
| Value | 0.375 |
| Percentage of DividendsPayableAmountPerShare | 0.0 |
| Period End | 2020-10-28 |
| Value | 0.3 |
| Percentage of DividendsPayableAmountPerShare | 0.0 |
| Period End | 2021-02-25 | 2020-06-30 | 2020-02-25 | 2018-10-28 |
| Value | 0.5 | 0.3 | 0.25 | 0.375 |
| Percentage of DividendsPayableAmountPerShare | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-02-25 | 2020-06-30 | 2020-02-25 | 2018-10-28 |
| Value | 0.375 | 0.25 | 0.175 | 0.3 |
| Percentage of DividendsPayableAmountPerShare | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-10-08 |
| Value | 0.29193 |
| Percentage of DividendsPayableAmountPerShare | 0.0 |
| Period End | 2021-01-11 |
| Value | 0.46094 |
| Percentage of DividendsPayableAmountPerShare | 0.0 |
| Period End | 2020-11-28 | 2020-08-28 | 2020-07-30 | 2020-01-09 | 2017-05-10 |
| Value | 0.375 | 0.05 | 0.3 | 0.42969 | 0.08 |
| Percentage of DividendsPayableAmountPerShare | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 |
| Value | 7.089 | 19 | 29 | 10 | 23 | 27 | 29 | 22 | 37 | 54 | 35 | 47 | 31 | 21 | 6.297 |
| Percentage of DueFromCorrespondentBrokers | 100.0 | 100.0 | 100.0 | 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 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-03-31 | 2012-12-31 |
| Value | 0.986 | 3.766 | 0.295 | 4.391 | 5.832 | 6.689 | 4.318 | 1.965 | 1.729 | 9.921 | 8.042 | 6.016 | 5.689 | 6.082 | 6.765 | 4.267 | 3.009 | 0.731 | 2.255 | 1.875 | 0.409 | 3.703 | 1.097 | 0.545 | 0.066 | 0.305 | 0.132 | 0.0 | 0.018 | 0.373 | 0.0 |
| Percentage of DueFromRelatedPartiesCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 |
| Value | 0.433 | 3.371 | 0.248 |
| Percentage of DueFromRelatedPartiesCurrent | 43.9 | 89.5 | 84.1 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 0.544 | 0.372 | 0.015 | 0.012 |
| Percentage of DueFromRelatedPartiesCurrent | 55.2 | 9.9 | 5.1 | 0.2 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 0.009 | 0.023 | 0.032 | 0.145 |
| Percentage of DueFromRelatedPartiesCurrent | 0.9 | 0.6 | 10.8 | 2.5 |
| 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 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-06-30 | 2012-12-31 |
| Value | 0.327 | 0.777 | 0.617 | 1.061 | 1.75 | 2.814 | 1.563 | 1.428 | 2.428 | 1.428 | 7.398 | 2.378 | 1.578 | 1.244 | 0.393 | 0.416 | 10 | 0.166 | 0.213 | 0.0 | 0.0 | 0.0 | 0.045 | 0.046 | 0.0 |
| Percentage of DueToRelatedPartiesCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | 100.0 | 0.0 |
| Period End | 2020-12-31 |
| Value | 11 |
| Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions | 100.0 |
| Period End | 2020-12-31 |
| Value | 3.686 |
| Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions | 33.0 |
| 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 | 2018-11-14 |
| Value | 45.2 | 45.3 | 0.457 | 0.468 | 0.468 | 0.488 | 0.488 | 0.24 | 0.24 | 0.24 |
| Percentage of EquityMethodInvestmentOwnershipPercentage | 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 |
| Value | 49.6 | 43.8 | 0.729 | 0.698 | 0.653 | 0.585 |
| Percentage of EquityMethodInvestmentOwnershipPercentage | 109.7 | 96.7 | 159.5 | 149.1 | 139.5 | 119.9 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 39.2 | 38.5 |
| Percentage of EquityMethodInvestmentOwnershipPercentage | 86.7 | 85.0 |
| Period End | 2021-03-02 |
| Value | 80.0 |
| Percentage of EquityMethodInvestmentOwnershipPercentage | 0.0 |
| Period End | 2021-03-02 |
| Value | 40.0 |
| Percentage of EquityMethodInvestmentOwnershipPercentage | 0.0 |
| Period End | 2021-03-02 |
| Value | 16.0 |
| Percentage of EquityMethodInvestmentOwnershipPercentage | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 13.7 | 0.137 |
| Percentage of EquityMethodInvestmentOwnershipPercentage | 30.3 | 29.3 |
| Period End | 2020-09-30 | 2020-06-30 |
| Value | 10.0 | 0.1 |
| Percentage of EquityMethodInvestmentOwnershipPercentage | 22.1 | 21.9 |
| Period End | 2021-02-12 |
| Value | 8.125 |
| Percentage of EquityMethodInvestmentOwnershipPercentage | 0.0 |
| Period End | 2021-03-02 |
| Value | 16.0 |
| Percentage of EquityMethodInvestmentOwnershipPercentage | 0.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 54 | 51 |
| Percentage of EquityMethodInvestments | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2018-12-31 |
| Value | 390 | 344 | 325 | 43 | 35 | 41 | 33 |
| Percentage of FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2018-12-31 |
| Value | 4.7 | 4.462 | 4.351 | 4.616 | 4.395 | 4.224 | 4.633 |
| Percentage of FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue | 1.2 | 1.3 | 1.3 | 10.7 | 12.4 | 10.1 | 13.7 |
| 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 | 2017-12-31 |
| Value | 149 | 102 | 107 | 95 | 109 | 50 | 32 | 24 | 24 | 28 |
| Percentage of FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue | 38.2 | 29.7 | 33.1 | 0.0 | 252.1 | 143.4 | 78.0 | 0.0 | 72.9 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2017-12-31 |
| Value | 57 | 49 | 29 | 27 | 20 | 19 | 23 | 23 | 3.59 |
| Percentage of FairValueNetAssetLiability | 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 |
| Value | 4.7 | 4.462 |
| Percentage of FinancialLiabilitiesFairValueDisclosure | 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 | 2015-12-31 |
| Value | 48 | 44 | 41 | 37 | 33 | 29 | 26 | 23 | 19 | 17 | 15 | 13 | 11 | 9.008 | 6.837 | 5.301 | 3.826 | 2.26 | 0.572 |
| Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| 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 | 2016-09-30 |
| Value | 0.056 | 0.053 | 0.05 | 0.047 | 0.044 | 0.041 | 0.038 | 0.044 | 0.031 | 0.003 |
| Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.2 | 0.2 | 0.1 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 0.148 | 0.14 | 0.132 | 0.123 | 0.117 | 0.108 | 0.1 | 0.117 | 0.085 |
| Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization | 0.3 | 0.3 | 0.3 | 0.3 | 0.3 | 0.4 | 0.4 | 0.5 | 0.4 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 6.913 | 6.49 | 6.068 | 5.456 | 4.843 | 4.23 | 3.618 | 4.843 | 2.436 |
| Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization | 14.3 | 14.5 | 14.6 | 14.5 | 14.4 | 14.2 | 13.7 | 20.8 | 12.2 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2014-12-31 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2011-12-31 |
| Value | 40 | 37 | 33 | 30 | 27 | 24 | 21 | 27 | 16 | 1.948 | 0.795 | 0.684 | 0.572 | 0.141 | 0.97 | 0.97 | 0.97 | 0.97 | 0.97 | 0.97 | 0.97 |
| Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization | 83.2 | 83.0 | 81.1 | 81.2 | 81.2 | 81.3 | 81.9 | 117.3 | 83.4 | 86.2 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 0.991 | 0.912 | 1.605 | 1.465 | 1.324 | 1.184 | 1.043 | 1.324 | 0.762 |
| Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization | 2.0 | 2.0 | 3.9 | 3.9 | 3.9 | 4.0 | 3.9 | 5.7 | 3.8 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 10 | 15 |
| Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 14 |
| Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 14 | 14 |
| Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths | 100.0 | 100.0 |
| Period End | 2020-09-30 |
| Value | 3769000.0 |
| Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 5151000.0 | 8376000.0 |
| Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearFour | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 8.378 | 12 |
| Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearThree | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 12 | 14 |
| Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo | 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 | 2015-12-31 |
| Value | 113 | 113 | 115 | 115 | 115 | 107 | 106 | 111 | 111 | 68 | 67 | 68 | 68 | 68 | 51 | 44 | 44 | 41 | 3.6 |
| Percentage of FiniteLivedIntangibleAssetsGross | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 0.235 | 0.235 | 0.235 | 0.23 | 0.223 | 0.233 | 0.233 | 0.233 | 0.237 |
| Percentage of FiniteLivedIntangibleAssetsGross | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 11 | 11 | 11 | 11 | 11 | 11 | 11 | 11 | 11 |
| Percentage of FiniteLivedIntangibleAssetsGross | 10.3 | 10.3 | 10.2 | 10.2 | 10.2 | 11.0 | 11.0 | 10.5 | 10.6 |
| 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 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2014-12-31 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2011-12-31 |
| Value | 98 | 98 | 99 | 99 | 99 | 90 | 90 | 99 | 92 | 36 | 3.6 | 3.6 | 3.6 | 1.2 | 0.97 | 0.97 | 0.97 | 0.97 | 0.97 | 0.97 | 0.97 |
| Percentage of FiniteLivedIntangibleAssetsGross | 86.9 | 86.9 | 85.6 | 85.6 | 85.6 | 84.4 | 84.4 | 88.6 | 83.0 | 89.1 | 0.0 | 0.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 2.85 | 2.85 | 4.6 | 4.6 | 4.6 | 4.6 | 4.6 | 4.6 | 4.6 |
| Percentage of FiniteLivedIntangibleAssetsGross | 2.5 | 2.5 | 4.0 | 4.0 | 4.0 | 4.3 | 4.3 | 4.1 | 4.1 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 190 | 194 | 199 | 212 | 220 | 79 | 82 | 220 | 91 |
| Percentage of IndefiniteLivedTradeNames | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 125 | 125 | 125 | 134 | 138 | 2.24 | 2.24 | 138 | 2.24 |
| Percentage of IndefiniteLivedTradeNames | 65.7 | 64.4 | 63.0 | 63.3 | 62.8 | 2.8 | 2.7 | 62.8 | 2.5 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 0.714 | 0.714 | 0.714 | 1.071 |
| Percentage of LettersOfCreditOutstandingAmount | 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 |
| Value | 4.575 | 42 | 4.181 | 0.124 | 5.36 | 6.684 | 15 | 10 | 11 | 52 | 12 | 15 | 26 | 23 | 2.594 |
| Percentage of LiabilitiesFairValueDisclosure | 100.0 | 100.0 | 100.0 | 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 | 2015-12-31 |
| Value | 5.53 | 6.039 | 5.623 | 14 | 36 | 22 | 26 | 25 | 26 | 6.979 | 5.353 | 4.436 | 1.874 | 1.477 | 0.932 | 1.659 | 0.846 | 0.713 |
| Percentage of LiabilitiesFairValueDisclosure | 120.9 | 14.3 | 134.5 | 11430.6 | 680.2 | 335.2 | 169.7 | 256.2 | 238.0 | 13.2 | 43.8 | 29.0 | 7.1 | 6.3 | 35.9 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2015-12-31 |
| Value | 4.7 | 4.462 | 4.351 | 4.508 | 4.616 | 4.395 | 4.224 | 4.529 | 4.633 | 4.409 | 4.238 | 4.536 | 4.478 | 12 | 9.641 | 3.19 | 4.456 | 4.721 |
| Percentage of LiabilitiesFairValueDisclosure | 102.7 | 10.6 | 104.1 | 3635.5 | 86.1 | 65.8 | 26.6 | 44.9 | 41.6 | 8.4 | 34.7 | 29.6 | 17.0 | 54.4 | 371.7 | 0.0 | 0.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2015-12-31 |
| Value | 14 | 52 | 14 | 18 | 46 | 33 | 46 | 40 | 42 | 64 | 21 | 24 | 32 | 37 | 13 | 4.849 | 5.302 | 5.434 |
| Percentage of LiabilitiesFairValueDisclosure | 323.6 | 125.0 | 338.6 | 15166.1 | 866.3 | 501.0 | 296.3 | 401.1 | 379.7 | 121.6 | 178.4 | 158.6 | 124.0 | 160.7 | 507.6 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-02 |
| Value | 8.0 |
| Percentage of LoansReceivableFairValueDisclosure | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 0.568 | 71 | 71 | 47 |
| Percentage of LoansReceivableFairValueDisclosure | 0.0 | 0.0 | 0.0 | 0.0 |
| Period End | 2021-03-02 |
| Value | 55 |
| Percentage of LoansReceivableFairValueDisclosure | 688.3 |
| Period End | 2021-02-23 |
| Value | 3.0 |
| Percentage of LoansReceivableFairValueDisclosure | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 |
| Value | 870 | 854 | 854 | 853 | 688 | 701 | 582 | 465 | 459 | 455 | 333 | 210 | 203 | 115 | 86 | 27 | 27 |
| Percentage of LongTermNotesPayable | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2021-03-02 |
| Value | 17 |
| Percentage of LongtermConstructionLoanCurrentAndNoncurrent | 100.0 |
| Period End | 2020-09-30 |
| Value | 731000.0 |
| Percentage of ManagementFeePayable | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 |
| Value | 30.5 | 0.305 | 0.305 | 0.305 |
| Percentage of MinorityInterestOwnershipPercentageByNoncontrollingOwners | 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 |
| Value | 50.0 | 50.0 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 |
| Percentage of MinorityInterestOwnershipPercentageByNoncontrollingOwners | 0.0 | 163.9 | 163.9 | 163.9 | 163.9 | 0.0 | 0.0 |
| Period End | 2020-12-31 |
| Value | 40.0 |
| Percentage of MinorityInterestOwnershipPercentageByNoncontrollingOwners | 0.0 |
| Period End | 2020-12-31 |
| Value | 39.5 |
| Percentage of MinorityInterestOwnershipPercentageByNoncontrollingOwners | 0.0 |
| Period End | 2020-12-31 |
| Value | 31.5 |
| Percentage of MinorityInterestOwnershipPercentageByNoncontrollingOwners | 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 |
| Value | 390 | 344 | 325 | 326 | 225 | 295 | 250 | 53 | 38 |
| Percentage of NotesAndLoansReceivableNetCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 232 | 232 | 225 |
| Percentage of NotesAndLoansReceivableNetCurrent | 67.4 | 71.3 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-03-31 |
| Value | 416 | 360 | 341 | 339 | 32 | 22 |
| Percentage of NotesAndLoansReceivableNetCurrent | 106.6 | 104.7 | 105.0 | 104.1 | 14.5 | 42.5 |
| Period End | 2020-12-31 |
| Value | 37 |
| Percentage of NotesPayable | 100.0 |
| Period End | 2021-03-02 |
| Value | 0.003 |
| Percentage of NotesPayable | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 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 | 295 | 236 | 233 | 216 | 157 | 0.0 | 0.0 | 0.0 | 0.0 | 0.703 | 0.686 | 0.377 | 0.415 | 0.611 | 0.68 | 3.75 | 3.844 | 3.844 | 3.224 | 3.224 | 5.93 |
| Percentage of NotesReceivableRelatedPartiesCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 | 0.0 | 0.0 | 0.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 5.55 |
| Percentage of OperatingLeaseWeightedAverageDiscountRatePercent | 100.0 |
| Period End | 2020-12-31 |
| Value | 73 |
| Percentage of OperatingLeasesFutureMinimumPaymentsDue | 100.0 |
| Period End | 2020-12-31 |
| Value | 9558000.0 |
| Percentage of OperatingLeasesFutureMinimumPaymentsDueInFiveYears | 100.0 |
| Period End | 2020-12-31 |
| Value | 9934000.0 |
| Percentage of OperatingLeasesFutureMinimumPaymentsDueInFourYears | 100.0 |
| Period End | 2020-12-31 |
| Value | 10 |
| Percentage of OperatingLeasesFutureMinimumPaymentsDueInThreeYears | 100.0 |
| Period End | 2020-12-31 |
| Value | 11 |
| Percentage of OperatingLeasesFutureMinimumPaymentsDueInTwoYears | 100.0 |
| Period End | 2020-12-31 |
| Value | 21 |
| Percentage of OperatingLeasesFutureMinimumPaymentsDueThereafter | 100.0 |
| Period End | 2020-12-31 |
| Value | 11 |
| Percentage of OperatingLeasesFutureMinimumPaymentsRemainderOfFiscalYear | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 |
| Value | 63 | 53 | 64 | 53 | 53 |
| Percentage of OperatingLossCarryforwards | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 47 |
| Percentage of OperatingLossCarryforwards | 74.3 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2012-12-31 | 2011-12-31 |
| Value | 64 | 53 | 64 | 64 | 61 | 61 | 65 | 65 | 76 | 76 | 76 | 76 | 77 | 39 | 11 | 19 | 13 | 13 | 13 | 13 | 19 | 19 | 19 | 19 | 22 | 22 | 21 | 21 | 14 | 21 |
| Percentage of OperatingLossCarryforwards | 118.8 | 84.2 | 118.8 | 118.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 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 | 2019-12-31 |
| Value | 17 | 13 | 14 | 12 |
| Percentage of OtherLoansPayable | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 74 | 52 | 57 | 66 |
| Percentage of OtherLongTermDebtNoncurrent | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 |
| Value | 25000.0 |
| Percentage of PreferredStockLiquidationPreference | 100.0 |
| Period End | 2020-09-30 |
| Value | 25000.0 |
| Percentage of PreferredStockLiquidationPreference | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 |
| Value | 99 | 95 | 63 | 63 | 58 |
| Percentage of PreferredStockLiquidationPreferenceValue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 |
| Value | 64 | 63 | 58 |
| Percentage of PreferredStockLiquidationPreferenceValue | 65.0 | 66.1 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 |
| Value | 34 | 32 |
| Percentage of PreferredStockLiquidationPreferenceValue | 35.0 | 33.9 |
| 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 | 4.7 | 4.462 | 4.351 | 4.508 | 4.616 | 4.395 | 4.224 | 4.529 | 4.633 | 4.409 | 4.238 | 4.536 | 4.478 | 12 | 9.641 | 3.19 | 3.214 | 2.33 |
| Percentage of RedeemableNoncontrollingInterestEquityFairValue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2015-12-31 |
| Value | 4.7 | 4.462 | 4.351 | 4.508 | 4.616 | 4.395 | 4.224 | 4.529 | 4.633 | 4.409 | 4.238 | 4.536 | 4.478 | 12 | 9.641 | 3.19 | 3.214 | 2.33 |
| Percentage of RedeemableNoncontrollingInterestEquityFairValue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 4.697 |
| Percentage of RelatedPartyTransactionDueFromToRelatedParty | 100.0 |
| Period End | 2021-02-12 |
| Value | 35 |
| Percentage of RelatedPartyTransactionDueFromToRelatedParty | 0.0 |
| Period End | 2021-02-12 |
| Value | 35 |
| Percentage of RelatedPartyTransactionDueFromToRelatedParty | 0.0 |
| Period End | 2020-12-31 | 2019-06-30 | 2019-03-31 | 2018-12-31 |
| Value | 764000.0 | 2635000.0 | 7491000.0 | 838000.0 |
| Percentage of RestrictedCash | 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 | 2011-12-31 |
| Value | 1.235 | 1.41 | 0.471 | 0.471 | 0.471 | 0.471 | 2.635 | 7.491 | 0.838 | 0.468 | 0.467 | 23 | 19 | 9.269 | 5.632 | 0.518 | 3.294 | 78 | 12 | 0.052 | 0.051 | 0.124 | 0.502 | 25 | 7.657 | 3.578 | 0.132 | 0.08 | 0.325 | 2.538 | 1.225 | 0.23 | 7.923 | 6.767 | 0.1 | 0.0 |
| Percentage of RestrictedCashAndCashEquivalentsAtCarryingValue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 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 | 727000.0 | 793000.0 | 979000.0 | 1284000.0 | 1600000.0 | 1923000.0 | 2642000.0 | 3384000.0 | 3855000.0 | 1750000.0 | 1827000.0 | 1576000.0 | 2600000.0 | 3359000.0 | 3287000.0 | 817000.0 | 694000.0 | 187000.0 |
| Percentage of RestructuringReserve | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 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 | 2021-01-15 | 2020-02-28 | 2020-01-31 |
| Value | 46.0 | 24.473 | 24.473 |
| Percentage of SaleOfStockPricePerShare | 100.0 | 100.0 | 100.0 |
| Period End | 2021-01-23 |
| Value | 300 |
| Percentage of SecuredDebt | 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 |
| Value | 765 | 676 | 786 | 674 | 814 | 720 | 759 | 827 | 931 | 1042 | 1013 | 861 | 807 | 730 | 909 |
| Percentage of SecuritiesBorrowed | 100.0 | 100.0 | 100.0 | 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 |
| Value | 765 | 676 | 786 | 674 | 814 | 720 | 759 | 827 | 931 | 1042 | 1013 | 861 | 807 |
| Percentage of SecuritiesBorrowedGross | 100.0 | 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 |
| Value | 765 | 676 | 786 | 674 | 814 | 720 | 759 | 827 | 931 | 1042 | 1013 | 861 | 807 |
| Percentage of SecuritiesBorrowedOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection | 100.0 | 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 |
| Value | 759 | 667 | 779 | 670 | 810 | 714 | 759 | 824 | 930 | 1035 | 1012 | 854 | 803 | 728 | 911 |
| Percentage of SecuritiesLoaned | 100.0 | 100.0 | 100.0 | 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 |
| Value | 759 | 667 | 779 | 670 | 810 | 714 | 759 | 824 | 930 | 1035 | 1012 | 854 | 803 |
| Percentage of SecuritiesLoanedGross | 100.0 | 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 |
| Value | 759 | 667 | 779 | 670 | 810 | 714 | 759 | 824 | 930 | 1035 | 1012 | 854 | 803 |
| Percentage of SecuritiesLoanedOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection | 100.0 | 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 | 2015-12-31 |
| Value | 777 | 459 | 399 | 287 | 451 | 326 | 270 | 288 | 273 | 222 | 160 | 150 | 145 | 95 | 78 | 41 | 16 | 9.028 | 24 | 25 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 697 | 353 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 89.7 | 78.2 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2018-12-31 |
| Value | 290 | 233 | 139 | 243 | 168 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 63.2 | 58.6 | 48.6 | 54.0 | 61.7 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2018-12-31 |
| Value | 102 | 107 | 95 | 109 | 24 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 22.3 | 27.0 | 33.1 | 24.2 | 9.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2018-12-31 |
| Value | 392 | 341 | 234 | 353 | 193 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 85.5 | 85.6 | 81.6 | 78.2 | 70.7 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2018-12-31 | 2016-09-30 | 2016-06-30 | 2015-12-31 |
| Value | 521 | 290 | 233 | 139 | 243 | 193 | 147 | 168 | 1.077 | 19 | 17 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 67.0 | 63.2 | 58.6 | 48.6 | 54.0 | 59.3 | 54.5 | 61.7 | 11.9 | 78.3 | 67.7 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2018-12-31 | 2016-09-30 | 2016-06-30 | 2015-12-31 |
| Value | 5.108 | 9.513 | 8.143 | 23 | 27 | 26 | 28 | 22 | 5.115 | 2.23 | 6.191 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 0.7 | 2.1 | 2.0 | 8.2 | 6.1 | 8.1 | 10.7 | 8.3 | 56.7 | 9.0 | 24.2 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2018-12-31 | 2016-09-30 | 2016-06-30 | 2015-12-31 |
| Value | 149 | 102 | 107 | 95 | 43 | 86 | 58 | 2.836 | 3.119 | 2.056 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 19.2 | 22.3 | 27.0 | 33.1 | 9.6 | 26.5 | 21.3 | 31.4 | 12.7 | 8.0 |
| Period End | 2020-12-31 |
| Value | 521 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 67.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 3.195 | 19 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 0.4 | 4.2 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2018-12-31 |
| Value | 5.956 | 5.375 | 18 | 19 | 21 | 23 | 18 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 1.3 | 1.3 | 6.4 | 4.2 | 6.6 | 8.6 | 6.9 |
| Period End | 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 | 1.913 | 3.557 | 2.768 | 5.243 | 8.414 | 4.816 | 5.767 | 3.825 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 0.2 | 0.8 | 0.7 | 1.8 | 1.9 | 1.5 | 2.1 | 1.4 |
| Period End | 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 | 390 | 344 | 325 | 326 | 43 | 35 | 41 | 33 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 50.3 | 74.9 | 81.6 | 113.4 | 9.6 | 10.9 | 15.5 | 12.3 |
| Period End | 2020-12-31 |
| Value | 149 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 19.2 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2018-12-31 | 2016-09-30 | 2016-06-30 | 2015-12-31 |
| Value | 675 | 459 | 399 | 287 | 423 | 306 | 250 | 249 | 9.028 | 24 | 25 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 86.9 | 100.0 | 100.0 | 100.0 | 93.9 | 93.8 | 92.8 | 91.3 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 3.195 | 19 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 0.4 | 4.2 |
| Period End | 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 | 390 | 344 | 325 | 326 | 43 | 35 | 41 | 33 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 50.3 | 74.9 | 81.6 | 113.4 | 9.6 | 10.9 | 15.5 | 12.3 |
| Period End | 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 | 670 | 5.956 | 5.375 | 18 | 19 | 21 | 23 | 18 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 86.2 | 1.3 | 1.3 | 6.4 | 4.2 | 6.6 | 8.6 | 6.9 |
| Period End | 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 | 1.913 | 3.557 | 2.768 | 5.243 | 8.414 | 4.816 | 5.767 | 3.825 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 0.2 | 0.8 | 0.7 | 1.8 | 1.9 | 1.5 | 2.1 | 1.4 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 3.195 | 19 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 0.4 | 4.2 |
| Period End | 2020-12-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2018-12-31 |
| Value | 74 | 27 | 20 | 19 | 23 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 9.6 | 6.1 | 6.2 | 7.2 | 8.7 |
| Period End | 2020-12-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2018-12-31 |
| Value | 1.913 | 8.414 | 4.816 | 5.767 | 3.825 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityOwned | 0.2 | 1.9 | 1.5 | 2.1 | 1.4 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 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 |
| Value | 10 | 48 | 9.804 | 14 | 41 | 29 | 42 | 35 | 37 | 59 | 17 | 19 | 28 | 25 | 3.526 | 1.659 | 0.846 | 0.37 | 5.932 | 0.953 | 0.713 | 6.481 | 8.057 | 0.956 | 0.746 | 2.811 | 6.489 | 0.0 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2018-12-31 |
| Value | 4.575 | 42 | 4.181 | 0.124 | 5.36 | 11 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 45.3 | 87.5 | 42.6 | 0.9 | 12.8 | 29.6 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2018-12-31 |
| Value | 42 | 4.181 | 0.124 | 5.36 | 11 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 87.5 | 42.6 | 0.9 | 12.8 | 29.6 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2018-12-31 |
| Value | 42 | 4.181 | 0.124 | 5.36 | 11 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 87.5 | 42.6 | 0.9 | 12.8 | 29.6 |
| 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 |
| Value | 4.575 | 42 | 4.181 | 0.124 | 5.36 | 6.684 | 15 | 10 | 11 | 52 | 12 | 15 | 26 | 23 | 2.594 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 45.3 | 87.5 | 42.6 | 0.9 | 12.8 | 23.0 | 37.1 | 28.1 | 29.6 | 88.3 | 69.6 | 77.5 | 93.4 | 94.1 | 73.6 |
| 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 |
| Value | 5.53 | 6.039 | 5.623 | 14 | 36 | 22 | 26 | 25 | 26 | 6.979 | 5.353 | 4.436 | 1.874 | 1.477 | 0.932 | 1.659 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 54.7 | 12.5 | 57.4 | 99.1 | 87.2 | 77.0 | 62.9 | 71.9 | 70.4 | 11.7 | 30.4 | 22.5 | 6.6 | 5.9 | 26.4 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 4.575 | 5.36 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 45.3 | 12.8 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 4.288 | 33 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 42.4 | 80.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2015-12-31 |
| Value | 4.49 | 5.272 | 13 | 33 | 18 | 21 | 20 | 16 | 6.381 | 2.74 | 4.102 | 1.175 | 0.982 | 0.932 | 1.554 | 0.846 | 0.713 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 9.3 | 53.8 | 93.4 | 80.0 | 64.0 | 49.5 | 56.2 | 43.4 | 10.7 | 15.6 | 20.8 | 4.2 | 3.9 | 26.4 | 93.7 | 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 |
| Value | 1.242 | 1.549 | 0.351 | 0.813 | 3.024 | 3.778 | 5.741 | 5.651 | 10 | 0.598 | 2.613 | 0.334 | 0.699 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 12.3 | 3.2 | 3.6 | 5.7 | 7.2 | 13.0 | 13.4 | 15.7 | 27.0 | 1.0 | 14.9 | 1.7 | 2.5 |
| 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 |
| Value | 10 | 48 | 9.804 | 14 | 41 | 29 | 42 | 35 | 37 | 59 | 17 | 19 | 28 | 25 | 3.526 | 1.659 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 4.288 | 33 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 42.4 | 80.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 4.575 | 5.36 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 45.3 | 12.8 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2015-12-31 |
| Value | 4.49 | 5.272 | 13 | 33 | 18 | 21 | 20 | 16 | 6.381 | 2.74 | 4.102 | 1.175 | 0.982 | 0.932 | 1.554 | 0.846 | 0.713 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 9.3 | 53.8 | 93.4 | 80.0 | 64.0 | 49.5 | 56.2 | 43.4 | 10.7 | 15.6 | 20.8 | 4.2 | 3.9 | 26.4 | 93.7 | 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 |
| Value | 1.242 | 1.549 | 0.351 | 0.813 | 3.024 | 3.778 | 5.741 | 5.651 | 10 | 0.598 | 2.613 | 0.334 | 0.699 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 12.3 | 3.2 | 3.6 | 5.7 | 7.2 | 13.0 | 13.4 | 15.7 | 27.0 | 1.0 | 14.9 | 1.7 | 2.5 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 4.288 | 4.49 | 5.272 | 33 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 42.4 | 9.3 | 53.8 | 80.0 |
| 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 |
| Value | 1.242 | 1.549 | 0.351 | 0.813 | 3.024 | 3.778 | 5.741 | 5.651 | 10 | 0.598 | 2.613 | 0.334 | 0.699 |
| Percentage of SecurityOwnedAndSoldNotYetPurchasedFairValueSecuritySoldNotYetPurchased | 12.3 | 3.2 | 3.6 | 5.7 | 7.2 | 13.0 | 13.4 | 15.7 | 27.0 | 1.0 | 14.9 | 1.7 | 2.5 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2013-12-31 |
| Value | 459 | 399 | 287 | 451 | 326 | 270 | 288 | 273 | 222 | 160 | 150 | 145 | 95 | 78 | 41 | 16 | 25 | 25 | 17 | 13 | 10 | 17 | 16 | 2.985 | 0.0 |
| Percentage of SecurityOwnedNotReadilyMarketableFairValue | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 0.0 |
| Period End | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2018-12-31 |
| Value | 392 | 341 | 234 | 353 | 193 |
| Percentage of SecurityOwnedNotReadilyMarketableFairValue | 85.5 | 85.6 | 81.6 | 78.2 | 70.7 |
| Period End | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 5.956 | 5.375 | 19 |
| Percentage of SecurityOwnedNotReadilyMarketableFairValue | 1.3 | 1.3 | 4.2 |
| 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 | 57 | 49 | 29 | 27 | 20 | 19 | 23 | 23 | 56 | 47 | 41 | 35 | 21 | 13 |
| Percentage of SecurityOwnedNotReadilyMarketableFairValue | 12.5 | 12.4 | 10.2 | 6.1 | 6.2 | 7.2 | 8.1 | 8.7 | 25.3 | 29.7 | 27.3 | 24.4 | 22.3 | 81.2 |
| 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 |
| Value | 3.557 | 2.768 | 5.243 | 8.414 | 4.816 | 5.767 | 13 | 3.825 | 4.467 | 5.76 | 2.896 | 2.329 |
| Percentage of SecurityOwnedNotReadilyMarketableFairValue | 0.8 | 0.7 | 1.8 | 1.9 | 1.5 | 2.1 | 4.6 | 1.4 | 2.0 | 3.6 | 1.9 | 1.6 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2019-12-31 |
| Value | 870 | 854 | 854 | 688 |
| Percentage of SeniorLongTermNotes | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | 870 | 854 | 854 | 853 |
| Percentage of SeniorNotes | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 |
| Value | 898 | 845 | 772 | 666 |
| Percentage of SeniorNotes | 103.2 | 98.9 | 90.5 | 78.1 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 |
| Value | 19.33 | 18.33 | 17.64 |
| Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue | 100.0 | 100.0 | 100.0 |
| Period End | 2020-09-30 | 2020-07-01 | 2020-06-30 |
| Value | 22.36 | 22.0 | 22.39 |
| Percentage of SharePrice | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 | 2018-12-31 |
| Value | 19.29 | 12.35 | 16.94 |
| Percentage of SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 |
| Value | 6.0 |
| Percentage of ShortTermDebtPercentageBearingFixedInterestRate | 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 | 2016-12-31 |
| Value | 9.557 | 10 | 10 | 11 | 8.875 | 10 | 8.671 | 7.165 | 7.464 | 7.727 | 6.575 | 4.528 | 4.6 | 1.05 |
| Percentage of UnamortizedDebtIssuanceExpense | 100.0 | 100.0 | 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 | 2019-02-01 |
| Value | 0.787 | 0.385 | 0.524 |
| Percentage of UnamortizedDebtIssuanceExpense | 8.2 | 3.8 | 0.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2020-06-30 | 2020-03-31 | 2019-12-31 | 2019-09-30 | 2019-06-30 | 2019-03-31 | 2018-12-31 | 2018-09-30 | 2018-06-30 | 2018-03-31 | 2017-12-31 | 2017-09-30 | 2017-06-30 | 2017-03-31 | 2016-12-31 | 2016-09-30 | 2016-06-30 | 2016-03-31 | 2015-12-31 | 2015-09-30 | 2015-06-30 | 2015-03-31 | 2014-12-31 | 2014-09-30 | 2014-06-30 | 2014-03-31 | 2013-12-31 | 2013-09-30 | 2013-06-30 | 2013-03-31 | 2012-12-31 | 2012-09-30 | 2012-06-30 | 2011-12-31 |
| Value | 5.712 | 5.738 | 4.165 | 4.581 | 3.71 | 4.721 | 12 | 12 | 3.644 | 0.966 | 10 | 4.578 | 1.023 | 1.26 | 1.189 | 3.109 | 2.058 | 2.188 | 0.295 | 0.497 | 0.435 | 0.237 | 0.401 | 2.24 | 1.421 | 0.933 | 0.512 | 1.236 | 0.731 | 1.505 | 0.992 | 0.252 | 0.612 | 0.151 | 0.231 | 0.077 |
| Percentage of UnbilledReceivablesCurrent | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| Period End | 2020-12-31 | 2019-12-31 |
| Value | 5.712 | 3.71 |
| Percentage of UnbilledReceivablesCurrent | 100.0 | 100.0 |
| Period End | 2021-01-23 |
| Value | 100 |
| Percentage of UnsecuredDebt | 100.0 |
| Period End | 2020-12-31 | 2020-09-30 | 2019-12-31 |
| Value | 86 | 20 | 12 |
| Percentage of VariableInterestEntityEntityMaximumLossExposureAmount | 100.0 | 100.0 | 100.0 |
