Consolidated Statements of Stockholders' Equity (USD $) In Thousands, except Share data	Total	Common Stock	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive (Loss) Income	Treasury Stock
Beginning Balance at Dec. 31, 2009	$ 685,762	$ 435	$ 173,176	$ 628,234	$ (55,601)	$ (60,482)
Beginning Balance (in shares) at Dec. 31, 2009		38,284,000
Net income	144,646			144,646
Other comprehensive income (loss)	(7,425)				(7,425)
Dividends declared on common stock	(31,957)			(31,957)
Stock compensation expense	5,837		5,837
Stock option exercises, including tax benefit of $2,952 in 2010, $2,576 in 2011 and $580 in 2012 (in shares)		300,000
Stock option exercises, including tax benefit of $2,952 in 2010, $2,576 in 2011 and $580 in 2012	5,624	3	5,621
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $408 in 2010, $1,856 in 2011 and $721 in 2012 (in shares)		67,000
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $408 in 2010, $1,856 in 2011 and $721 in 2012	(1,063)		(675)			(388)
Repurchases of common stock (in shares)		(7,107,000)
Repurchases of common stock	(247,825)					(247,825)
Two-for-one stock split, net of treasury shares of 5,171 (in shares)		38,332,000
Two-for-one stock split, net of treasury shares of 5,171		435	(435)
Ending Balance at Dec. 31, 2010	553,599	873	183,524	740,923	(63,026)	(308,695)
Ending Balance (in shares) at Dec. 31, 2010		69,876,000
Net income	193,173			193,173
Other comprehensive income (loss)	(52,256)				(52,256)
Dividends declared on common stock	(31,109)			(31,109)
Stock compensation expense	7,692		7,692
Stock option exercises, including tax benefit of $2,952 in 2010, $2,576 in 2011 and $580 in 2012 (in shares)		217,000
Stock option exercises, including tax benefit of $2,952 in 2010, $2,576 in 2011 and $580 in 2012	4,451	2	4,449
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $408 in 2010, $1,856 in 2011 and $721 in 2012 (in shares)		232,000
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $408 in 2010, $1,856 in 2011 and $721 in 2012	(3,341)		(621)			(2,720)
Repurchases of common stock (in shares)	(441,416)	(441,000)
Repurchases of common stock	(15,797)					(15,797)
Other	1,582		1,582
Ending Balance at Dec. 31, 2011	657,994	875	196,626	902,987	(115,282)	(327,212)
Ending Balance (in shares) at Dec. 31, 2011	69,883,808	69,884,000
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, including tax benefit of $2,952 in 2010, $2,576 in 2011 and $580 in 2012 (in shares)	36,533	36,000
Stock option exercises, including tax benefit of $2,952 in 2010, $2,576 in 2011 and $580 in 2012	775	1	774
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $408 in 2010, $1,856 in 2011 and $721 in 2012 (in shares)		89,000
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $408 in 2010, $1,856 in 2011 and $721 in 2012	(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	69,203,967	69,204,000