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 $843 in 2012 and $552 in 2013 (in shares)		81,000
Repurchases of common stock (in shares)		(511,000)
Net income	43,330			43,330
Other comprehensive loss	(6,196)				(6,196)
Dividends declared on common stock	(16,947)			(16,947)
Stock compensation expense	3,479		3,479
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 $843 in 2012 and $552 in 2013	(849)		45			(894)
Repurchases of common stock	(22,086)					(22,086)
Ending Balance at Jun. 30, 2012	659,500	876	200,924	929,370	(121,478)	(350,192)
Ending Balance (in shares) at Jun. 30, 2012		69,490,000
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 $843 in 2012 and $552 in 2013 (in shares)		76,000
Repurchases of common stock (in shares)		(5,831,000)
Net income	84,962			84,962
Other comprehensive loss	(9,969)				(9,969)
Dividends declared on common stock	(18,144)			(18,144)
Stock compensation expense	4,354		4,354
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $843 in 2012 and $552 in 2013	(1,608)		(286)			(1,322)
Repurchases of common stock	(265,340)					(265,340)
Ending Balance at Jun. 30, 2013	$ 547,898	$ 876	$ 208,517	$ 1,087,361	$ (119,882)	$ (628,974)
Ending Balance (in shares) at Jun. 30, 2013		63,449,000