Consolidated Statements of Stockholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock [Member]	Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]
Beginning Balance at Dec. 31, 2011	$ 657,994	$ 875	$ 196,626	$ 902,987	$ (115,282)	$ (327,212)
Beginning Balance (in shares) at Dec. 31, 2011		69,884,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	151,346			151,346
Other comprehensive income (loss)	5,369				5,369
Dividends declared on common stock	(33,790)			(33,790)
Stock compensation expense	7,208		7,208
Stock option exercises (in shares)		36,000
Stock option exercises, including tax benefit	775	1	774
Net issuance of treasury stock for vested restricted stock units (in shares)		89,000
Net issuance of treasury stock for vested restricted stock units, including tax benefit	(1,150)		(159)			(991)
Repurchases of common stock (in shares)	(805,346)	(805,000)
Repurchases of common stock	(34,109)					(34,109)
Ending Balance at Dec. 31, 2012	753,643	876	204,449	1,020,543	(109,913)	(362,312)
Ending Balance (in shares) at Dec. 31, 2012		69,204,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	185,413			185,413
Other comprehensive income (loss)	71,794				71,794
Dividends declared on common stock	(36,202)			(36,202)
Stock compensation expense	8,902		8,902
Net issuance of treasury stock for vested restricted stock units (in shares)		90,000
Net issuance of treasury stock for vested restricted stock units, including tax benefit	(2,100)		(529)			(1,571)
Repurchases of common stock (in shares)	(354,154)	(5,879,000)
Repurchases of common stock	(267,607)					(267,607)
Ending Balance at Dec. 31, 2013	713,843	876	212,822	1,169,754	(38,119)	(631,490)
Ending Balance (in shares) at Dec. 31, 2013	63,415,444	63,415,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	182,391			182,391
Other comprehensive income (loss)	(127,505)				(127,505)
Dividends declared on common stock	(38,624)			(38,624)
Stock compensation expense	12,718		12,718
Net issuance of treasury stock for vested restricted stock units (in shares)		297,000
Net issuance of treasury stock for vested restricted stock units, including tax benefit	(8,201)		(91)			(8,110)
Repurchases of common stock (in shares)	(508,667)	(509,000)
Repurchases of common stock	(24,666)					(24,666)
Ending Balance at Dec. 31, 2014	$ 709,956	$ 876	$ 225,449	$ 1,313,521	$ (165,624)	$ (664,266)
Ending Balance (in shares) at Dec. 31, 2014	63,203,361	63,203,000