CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Loss
Balance at beginning of period at Dec. 31, 2016	$ 2,408,267	$ 441,369	$ 1,790,832	$ (2,426,749)	$ 3,545,844	$ (943,029)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Loss	(1,054,579)				(1,054,579)
Other comprehensive income (loss), net of tax	161,243					161,243
Issuance of treasury stock for stock option exercises	1,775		(286)	2,061
Issuance of treasury stock for restricted stock units vesting	(14,351)		(48,528)	34,177
Deferred compensation	(34)		(288)	634	(380)
Share-based compensation	67,119		67,119
Dividend equivalents for restricted stock units	(270)		(458)		188
Dividends	(311,973)				(311,973)
Balance at end of period at Dec. 31, 2017	1,257,197	441,369	1,808,391	(2,389,877)	2,179,100	(781,786)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Loss	(533,299)				(533,299)
Other comprehensive income (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 Loss	(213,512)				(213,512)
Other comprehensive income (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)