Condensed Consolidated Statements Of Stockholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
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
Stock option exercises, including tax benefit of $580 (in shares)		36,000
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $905 in 2012 and $444 in 2013 (in shares)		89,000
Repurchases of common stock (in shares)		(799,000)
Net income	121,987			121,987
Other comprehensive income	10,502				10,502
Dividends declared on common stock	(25,371)			(25,371)
Stock compensation expense	5,283		5,283
Stock option exercises, including tax benefit of $580	775	1	774
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $905 in 2012 and $444 in 2013	(967)		24			(991)
Repurchases of common stock	(33,863)					(33,863)
Ending Balance at Sep. 30, 2012	736,340	876	202,707	999,603	(104,780)	(362,066)
Ending Balance (in shares) at Sep. 30, 2012		69,210,000
Beginning Balance at Dec. 31, 2012	753,643	876	204,449	1,020,543	(109,913)	(362,312)
Beginning Balance (in shares) at Dec. 31, 2012		69,204,000
Increase (Decrease) in Stockholders' Equity
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $905 in 2012 and $444 in 2013 (in shares)		90,000
Repurchases of common stock (in shares)		(5,879,000)
Net income	162,137			162,137
Other comprehensive income	3,694				3,694
Dividends declared on common stock	(27,173)			(27,173)
Stock compensation expense	6,835		6,835
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $905 in 2012 and $444 in 2013	(2,116)		(545)			(1,571)
Repurchases of common stock	(267,607)					(267,607)
Ending Balance at Sep. 30, 2013	$ 629,413	$ 876	$ 210,739	$ 1,155,507	$ (106,219)	$ (631,490)
Ending Balance (in shares) at Sep. 30, 2013		63,415,000