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, 2012	$ 853,598	$ 526	$ 1,250,975	$ (7,234)	$ (366,066)	$ (24,603)
Net income	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	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)
Net income	111,511				111,511
Other comprehensive income (loss), net of deferred income taxes	1,284					1,284
Payment of dividend	(139,041)		910	(1,999)	(137,952)
Exercise of stock options	1,777	1	1,776
Net tax benefit related to stock based compensation	(2)		(2)
Restricted stock units and stock options surrendered	(3,532)	2	(3,534)
Stock-based compensation expense	6,158		6,158
Ending Balance at Dec. 31, 2015	$ 379,562	$ 513	$ 887,501	$ (10,001)	$ (473,404)	$ (25,047)