Stockholders' Equity - Schedule of Stockholders' Equity (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Sep. 30, 2019
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	$ 2,263,934,000		$ 2,804,151,000
Beginning retained earnings adjustment	(101,000)
Non-cash stock compensation	1,576,000		1,984,000
Conversion of Class B shares to Class A shares	0		0
Purchase of treasury stock at cost	(145,806,000)		(29,203,000)
Exercise of stock options and vesting of restricted stock, net of shares withheld to satisfy tax withholding	(1,222,000)		25,614,000
Net (loss) income	(164,943,000)		98,316,000
Foreign currency translation adjustment, net of tax of $0	(59,761,000)		(330,116,000)
Minimum pension liability adjustment, net of tax of $0	(168,000)		(932,000)	$ (932,000)
Balance, end of period	1,893,489,000	$ 2,263,934,000	2,569,808,000
Foreign currency translation adjustment, tax	0	0	0
Pension adjustment, tax	0		0
Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	3,760,029,000		3,724,636,000
Non-cash stock compensation	1,576,000		1,984,000
Exercise of stock options and vesting of restricted stock, net of shares withheld to satisfy tax withholding	(1,223,000)		25,610,000
Balance, end of period	3,760,362,000	3,760,029,000	3,752,186,000
(Accumulated deficit) retained earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	(176,822,000)		436,509,000
Beginning retained earnings adjustment	(101,000)
Net (loss) income	(164,928,000)		99,615,000
Balance, end of period	(341,851,000)	(176,822,000)	536,124,000
Accumulated other comprehensive (loss) income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	(941,986,000)		(1,073,981,000)
Foreign currency translation adjustment, net of tax of $0	(59,743,000)		(330,875,000)
Minimum pension liability adjustment, net of tax of $0	(168,000)			(932,000)
Balance, end of period	(1,001,897,000)	(941,986,000)	(1,405,788,000)
Treasury stock at cost
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	(365,316,000)		(271,106,000)
Purchase of treasury stock at cost	145,806,000		(29,203,000)
Balance, end of period	(511,122,000)	(365,316,000)	(300,309,000)
Non-controlling interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	(12,882,000)		(12,812,000)
Net (loss) income	(15,000)		(1,299,000)
Foreign currency translation adjustment, net of tax of $0	(18,000)		759,000
Balance, end of period	$ (12,915,000)	$ (12,882,000)	$ (13,314,000)
Class A Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance of shares outstanding, beginning of period (in shares)	115,119,000
Balance of shares outstanding, end of period (in shares)	122,213,000	115,119,000
Class A Common Stock | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance of shares outstanding, beginning of period (in shares)	115,119,000		119,575,000
Balance, beginning of period	$ 548,000		$ 542,000
Conversion of Class B shares to Class A shares (in shares)	(17,248,000)		(18,000)
Conversion of Class B shares to Class A shares	$ (69,000)
Purchase of treasury stock at cost (in shares)	(10,401,000)		(1,619,000)
Exercise of stock options and vesting of restricted stock, net of shares withheld to satisfy tax withholding (in shares)	247,000		1,101,000
Exercise of stock options and vesting of restricted stock, net of shares withheld to satisfy tax withholding	$ 1,000		$ 4,000
Balance of shares outstanding, end of period (in shares)	122,213,000	115,119,000	119,075,000
Balance, end of period	$ 618,000	$ 548,000	$ 546,000
Class B Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance of shares outstanding, beginning of period (in shares)	90,792,000
Balance of shares outstanding, end of period (in shares)	73,544,000	90,792,000
Class B Common Stock | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance of shares outstanding, beginning of period (in shares)	90,792,000		90,831,000
Balance, beginning of period	$ 363,000		$ 363,000
Conversion of Class B shares to Class A shares (in shares)	(17,248,000)
Conversion of Class B shares to Class A shares	$ 69,000		$ 18,000
Balance of shares outstanding, end of period (in shares)	73,544,000	90,792,000	90,813,000
Balance, end of period	$ 294,000	$ 363,000	$ 363,000
Accretion of redeemable noncontrolling interests and equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accretion of redeemable noncontrolling interests and equity				$ (44,000)
Redeemable noncontrolling interests and equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accretion of redeemable noncontrolling interests and equity	(20,000)
Reclassification of redeemable noncontrolling interests and equity			38,000
Redeemable noncontrolling interests and equity | Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accretion of redeemable noncontrolling interests and equity	$ (20,000)
Redeemable noncontrolling interests and equity | Non-controlling interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reclassification of redeemable noncontrolling interests and equity			$ 38,000