CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common stock	Paid-in capital	Treasury stock	Accumulated other comprehensive income (loss)	Retained earnings (deficit)
Balance, beginning of period at Dec. 31, 2013		$ 340,047	$ 1,661,269	$ (64,435)	$ (117,726)	$ (1,074,617)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 177,521					177,521
Net common stock issued under share-based compensation plans		0	0
Reissuance of treasury stock, net			(6,680)	31,498		(29,791)
Tax benefit from share-based compensation			0
Equity compensation			6,472
Other comprehensive income	60,950				60,950
Balance, end of period at Sep. 30, 2014	984,508	340,047	1,661,061	(32,937)	(56,776)	(926,887)
Balance, beginning of period 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]
Net income	1,069,582					1,069,582
Net common stock issued under share-based compensation plans		44	(446)
Reissuance of treasury stock, net			(6,894)	29,575		(29,494)
Tax benefit from share-based compensation			2,113
Equity compensation			8,942
Other comprehensive income	38,194				38,194
Balance, end of period at Sep. 30, 2015	$ 2,148,519	$ 340,091	$ 1,667,307	$ (3,362)	$ (43,147)	$ 187,630