Consolidated Statements of Stockholders' Equity (USD $) In Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Other Comprehensive (Loss) Income [Member]
Beginning Balance at Dec. 31, 2011	$ 1,045,535	$ 484	$ 929,904	$ (4,599)	$ 155,777	$ (36,031)
Net income (loss)	(26,644)				(26,644)
Other comprehensive income (loss), net of deferred income taxes	11,428					11,428
Issuance of common stock	32,722	8	32,714
Repurchase of Company stock for retirement	(185,400)	(50)			(185,350)
Payment of dividend	(62,007)	67	250,410	(2,635)	(309,849)
Exercise of stock options	25,080	13	25,067
Net tax benefit related to stock based compensation	8,991		8,991
Employee stock plan purchases	252		252
Restricted stock units and stock options surrendered	(5,314)	4	(5,318)
Restricted stock shares surrendered	(9)		(9)
Stock-based compensation expense	8,964		8,964
Ending Balance at Dec. 31, 2012	853,598	526	1,250,975	(7,234)	(366,066)	(24,603)
Net income (loss)	118,352				118,352
Other comprehensive income (loss), net of deferred income taxes	15,484					15,484
Repurchase of Company stock for retirement	(100,028)	(23)	(30)		(99,975)
Repurchase and conversion of convertible notes	(42,581)	(2)	(37,710)		(4,869)
Payment of dividend	(102,206)		538	(532)	(102,212)
Exercise of stock options	5,223	3	5,220
Net tax benefit related to stock based compensation	(206)		(206)
Restricted stock units and stock options surrendered	(1,501)	1	(1,502)
Stock-based compensation expense	11,560		11,560
Ending Balance at Dec. 31, 2013	757,695	505	1,228,845	(7,766)	(454,770)	(9,119)
Net income (loss)	126,452				126,452
Other comprehensive income (loss), net of deferred income taxes	(17,212)					(17,212)
Repurchase and conversion of convertible notes	(54,322)		(51,996)		(2,326)
Repurchase of common stock warrants	(307,491)		(304,400)		(3,091)
Payment of dividend	(112,772)		692	(236)	(113,228)
Exercise of stock options	6,862	3	6,859
Net tax benefit related to stock based compensation	(302)		(302)
Restricted stock units and stock options surrendered	(3,276)	2	(3,278)
Stock-based compensation expense	5,773		5,773
Ending Balance at Dec. 31, 2014	$ 401,407	$ 510	$ 882,193	$ (8,002)	$ (446,963)	$ (26,331)