CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common stock	Paid-in capital	Treasury stock	Accumulated other comprehensive loss	Retained earnings (deficit)
Balance, beginning of year at Dec. 31, 2013		$ 340,047	$ 1,661,269	$ (64,435)	$ (117,726)	$ (1,074,617)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issuance		0	0
Net common stock issued under share-based compensation plans		0	0
Reissuance of treasury stock, net			(6,680)	31,498		(29,790)
Tax benefit from share-based compensation			0
Equity compensation			9,003
Reacquisition of convertible junior subordinated debentures-equity component			0
Purchases of common stock				0
Other comprehensive (loss) income	$ 36,385				36,385
Net income	251,949					251,949
Balance, end of year at Dec. 31, 2014	1,036,903	340,047	1,663,592	(32,937)	(81,341)	(852,458)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issuance		0	0
Net common stock issued under share-based compensation plans		50	(478)
Reissuance of treasury stock, net			(6,894)	29,575		(29,495)
Tax benefit from share-based compensation			2,116
Equity compensation			11,902
Reacquisition of convertible junior subordinated debentures-equity component			0
Purchases of common stock				0
Other comprehensive (loss) income	20,461				20,461
Net income	1,172,000					1,172,000
Balance, end of year at Dec. 31, 2015	2,236,140	340,097	1,670,238	(3,362)	(60,880)	290,047
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issuance		18,313	113,146
Net common stock issued under share-based compensation plans		990	(6,020)
Reissuance of treasury stock, net			(130)	130		0
Tax benefit from share-based compensation			67
Equity compensation			11,373
Reacquisition of convertible junior subordinated debentures-equity component			(6,337)
Purchases of common stock				(147,127)
Other comprehensive (loss) income	(14,220)				(14,220)
Net income	342,517					342,517
Balance, end of year at Dec. 31, 2016	$ 2,548,842	$ 359,400	$ 1,782,337	$ (150,359)	$ (75,100)	$ 632,564