CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-In Capital	Treasury Stock	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Loss
Balance at beginning of period at Dec. 31, 2017	$ 1,257,197	$ (19,149)	$ 441,369	$ 1,808,391	$ (2,389,877)	$ 2,179,100	$ (19,149)	$ (781,786)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	(533,299)					(533,299)
Other comprehensive loss, net of tax	(77,440)							(77,440)
Issuance of treasury stock for restricted stock units vesting	(9,488)			(44,547)	35,059
Deferred compensation	124			(77)	201
Share-based compensation	48,915			48,915
Dividend equivalents for restricted stock units	41					41
Balance at end of period at Dec. 31, 2018	666,901		441,369	1,812,682	(2,354,617)	1,626,693		(859,226)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	(213,512)					(213,512)
Other comprehensive loss, net of tax	(10,258)							(10,258)
Issuance of treasury stock for restricted stock units vesting	(7,510)			(42,930)	35,420
Deferred compensation	125			(151)	276
Share-based compensation	55,968			55,968
Balance at end of period at Dec. 31, 2019	491,714		441,369	1,825,569	(2,318,921)	1,413,181		(869,484)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	126,628					126,628
Other comprehensive loss, net of tax	(75,092)							(75,092)
Issuance of treasury stock for stock option exercises	64			(41)	105
Issuance of treasury stock for restricted stock units vesting	(7,263)			(42,830)	35,567
Deferred compensation	124			(186)	310
Share-based compensation	60,168			60,168
Balance at end of period at Dec. 31, 2020	$ 596,343		$ 441,369	$ 1,842,680	$ (2,282,939)	$ 1,539,809		$ (944,576)