Condensed Consolidated Statements Of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Beginning Balance (in shares) at Dec. 31, 2013		63,415
Increase (Decrease) in Stockholders' Equity
Net issuance of treasury stock for vested restricted stock units, including tax benefit (in shares)		153
Repurchases of common stock (in shares)		(158)
Ending Balance (in shares) at Jun. 30, 2014		63,410
Beginning Balance at Dec. 31, 2013	$ 713,843	$ 876	$ 212,822	$ 1,169,754	$ (38,119)	$ (631,490)
Increase (Decrease) in Stockholders' Equity
Net income	75,479			75,479
Other comprehensive loss	(6,294)				(6,294)
Dividends declared on common stock	(19,356)			(19,356)
Stock compensation expense	5,951		5,951
Net issuance of treasury stock for vested restricted stock units, including tax benefit	(4,230)		(628)			(3,602)
Repurchases of common stock	(7,735)					(7,735)
Ending Balance at Jun. 30, 2014	757,658	$ 876	218,145	1,225,877	(44,413)	(642,827)
Beginning Balance (in shares) at Dec. 31, 2014		63,203
Increase (Decrease) in Stockholders' Equity
Net issuance of treasury stock for vested restricted stock units, including tax benefit (in shares)		82
Repurchases of common stock (in shares)		(2,906)
Ending Balance (in shares) at Jun. 30, 2015		60,379
Beginning Balance at Dec. 31, 2014	709,956	$ 876	225,449	1,313,521	(165,624)	(664,266)
Increase (Decrease) in Stockholders' Equity
Net income	75,548			75,548
Other comprehensive loss	(17,155)				(17,155)
Dividends declared on common stock	(20,113)			(20,113)
Stock compensation expense	6,689		6,689
Net issuance of treasury stock for vested restricted stock units, including tax benefit	(1,767)		(21)			(1,746)
Repurchases of common stock	(170,132)					(170,132)
Ending Balance at Jun. 30, 2015	$ 583,026	$ 876	$ 232,117	$ 1,368,956	$ (182,779)	$ (836,144)