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Income Taxes - Reconciliation of U.S. Federal Statutory Tax Rate to Company's Effective Tax Rate (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income tax provision
Statutory U.S. federal tax rate	21.00%	21.00%	21.00%
State income taxes, net of federal benefit	3.50%	3.50%	3.70%
Foreign operations	(8.50%)	(471.20%)	1.30%
Compensation plans	5.80%	240.60%	1.60%
Changes in tax laws	3.00%	0.00%	0.00%
Change in valuation allowances	6.90%	(107.20%)	0.00%
Unrecognized tax benefits	(1.10%)	420.40%	0.50%
Affiliate divestments	(6.20%)	(120.40%)	0.00%
Reduction in carrying value of Affiliates	0.00%	0.00%	13.00%
Changes in U.S. tax provision to return	0.80%	(195.70%)	(1.00%)
Other	0.40%	72.00%	0.90%
Effective tax rate	16.00%	0.90%	25.40%
Parent Company
Income tax provision
Effective tax rate	25.60%	(137.00%)	41.00%
Non-Controlling Interests
Income tax provision
Effect of income from non-controlling interests	(9.60%)	137.90%	(15.60%)

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to noncontrolling interest income (loss) exempt from income taxes.

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