Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Class A common stock	Additional paid-in capital	Accumulated earnings	Accumulated earnings Cumulative Effect, Period of Adoption, Adjustment	Minimum pension liability	Foreign currency translation and other	Foreign currency translation and other Cumulative Effect, Period of Adoption, Adjustment	Non- controlling interests
Beginning balance (in shares) at Dec. 31, 2017			339,459,138
Beginning Balance at Dec. 31, 2017	$ 4,174,614	$ 0	$ 3,395	$ 1,220,508	$ 3,443,007	$ 3,964	$ (152,969)	$ (399,445)	$ (3,964)	$ 60,118
Net income	$ 1,065,948				1,063,219					2,729
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201601Member
Pension liability adjustments, net of tax	$ 1,315						1,315
Restricted stock awards vesting (in shares)			1,424,462
Restricted stock awards vesting			$ 14	(14)
Compensation expense for equity awards	128,171			128,171
Reclassification of stock incentive plan award from an equity award to a liability award	(9,074)			(9,074)
Units repurchased for payment of taxes on equity awards	(29,386)			(29,386)
Repurchase of common stock (in shares)			(3,980,656)
Repurchase of common stock	(161,034)		$ (40)	(160,994)
Foreign currency translation gain (loss)	(161,384)							(160,312)		(1,072)
Amounts reclassified from accumulated other comprehensive loss to interest expense, net of tax	2,439							2,439
Unrealized gains on interest rate swaps, net of tax	708							708
Unrealized holding (losses) gains on available for sale debt securities, net of tax	(971)							(971)
Contributions from non-controlling interests	25,355									25,355
Distributions to non-controlling interests	(13,413)									(13,413)
Legal entity restructuring, net	0
Other (in shares)			9,839
Other	(13,386)		$ 0	(198)	(5,506)		3,747	(8,817)		(2,612)
Ending balance (in shares) at Dec. 31, 2018			336,912,783
Ending balance at Dec. 31, 2018	5,009,902		$ 3,369	1,149,013	4,504,684		(147,907)	(570,362)		71,105
Net income	1,291,450				1,282,357					9,093
Pension liability adjustments, net of tax	944						944
Restricted stock awards vesting (in shares)			920,407
Restricted stock awards vesting			$ 9	(9)
Compensation expense for equity awards	127,738			127,738
Units repurchased for payment of taxes on equity awards	(18,426)			(18,426)
Repurchase of common stock (in shares)			(3,080,907)
Repurchase of common stock	(145,137)		$ (31)	(145,106)
Foreign currency translation gain (loss)	(14,092)							(14,047)		(45)
Amounts reclassified from accumulated other comprehensive loss to interest expense, net of tax	1,320							1,320
Unrealized gains on interest rate swaps, net of tax	0
Unrealized holding (losses) gains on available for sale debt securities, net of tax	2,101							2,101
Contributions from non-controlling interests	46,612							0		46,612
Distributions to non-controlling interests	(3,957)									(3,957)
Deconsolidation of investments	(76,349)									(76,349)
Legal entity restructuring, net	63,149							63,149
Other (in shares)			0
Other	(12,143)		$ 1	2,734	6,108		0	(14,946)		(6,040)
Ending balance (in shares) at Dec. 31, 2019			334,752,283
Ending balance at Dec. 31, 2019	6,273,112		$ 3,348	1,115,944	5,793,149		(146,963)	(532,785)		40,419
Net income	755,868				751,989					3,879
Pension liability adjustments, net of tax	7,343						7,343
Restricted stock awards vesting (in shares)			1,859,146
Restricted stock awards vesting			$ 19	(19)
Compensation expense for equity awards	60,391			60,391
Units repurchased for payment of taxes on equity awards	(43,835)			(43,835)
Repurchase of common stock (in shares)			(1,050,084)
Repurchase of common stock	(50,028)		$ (11)	(50,017)
Foreign currency translation gain (loss)	124,260							124,045		215
Amounts reclassified from accumulated other comprehensive loss to interest expense, net of tax	426							426
Unrealized gains on interest rate swaps, net of tax	0
Unrealized holding (losses) gains on available for sale debt securities, net of tax	1,436							1,436
Contributions from non-controlling interests	2,173									2,173
Distributions to non-controlling interests	(4,330)									(4,330)
Legal entity restructuring, net	0
Other	(6,729)		$ 0	(7,825)	(15,081)			16,772		(595)
Ending balance (in shares) at Dec. 31, 2020			335,561,345
Ending balance at Dec. 31, 2020	$ 7,120,087		$ 3,356	$ 1,074,639	$ 6,530,057		$ (139,620)	$ (390,106)		$ 41,761