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) Income	Treasury Stock
Beginning Balance at Dec. 31, 2008	$ 525,023	$ 433	$ 162,568	$ 498,177	$ (75,861)	$ (60,294)
Beginning Balance (in shares) at Dec. 31, 2008		38,026,000
Comprehensive income:
Net income	159,409			159,409
Changes in net prior service credit and actuarial losses, net of tax provision of $8,435 in 2009, tax benefit of $654 in 2010, and tax benefit of $16,045 in 2011	11,099				11,099
Change in fair value of derivatives, net of tax benefit of $664 in 2009, tax provision of $882 in 2010, and tax benefit of $65 in 2011	(735)				(735)
Foreign currency translation, net of tax provision of $1,272 in 2009, $6,248 in 2010, and $6,469 in 2011	9,896				9,896
Comprehensive income	179,669
Dividends declared on common stock	(29,352)			(29,352)
Stock compensation expense	4,910		4,910
Stock option exercises, including tax benefit of $3,413 in 2009, $2,952 in 2010, and $2,576 in 2011 (in shares)		211,000
Stock option exercises, including tax benefit of $3,413 in 2009, $2,952 in 2010, and $2,576 in 2011	6,342	2	6,340
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $282 in 2009, $408 in 2010, and $1,856 in 2011 (in shares)		47,000
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $282 in 2009, $408 in 2010, and $1,856 in 2011	(830)		(642)			(188)
Ending Balance at Dec. 31, 2009	685,762	435	173,176	628,234	(55,601)	(60,482)
Ending Balance (in shares) at Dec. 31, 2009		38,284,000
Comprehensive income:
Net income	144,646			144,646
Changes in net prior service credit and actuarial losses, net of tax provision of $8,435 in 2009, tax benefit of $654 in 2010, and tax benefit of $16,045 in 2011	(3,809)				(3,809)
Change in fair value of derivatives, net of tax benefit of $664 in 2009, tax provision of $882 in 2010, and tax benefit of $65 in 2011	1,200				1,200
Foreign currency translation, net of tax provision of $1,272 in 2009, $6,248 in 2010, and $6,469 in 2011	(4,816)				(4,816)
Comprehensive income	137,221
Dividends declared on common stock	(31,957)			(31,957)
Stock compensation expense	5,837		5,837
Stock option exercises, including tax benefit of $3,413 in 2009, $2,952 in 2010, and $2,576 in 2011 (in shares)		300,000
Stock option exercises, including tax benefit of $3,413 in 2009, $2,952 in 2010, and $2,576 in 2011	5,624	3	5,621
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $282 in 2009, $408 in 2010, and $1,856 in 2011 (in shares)		67,000
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $282 in 2009, $408 in 2010, and $1,856 in 2011	(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	69,875,873	69,876,000
Comprehensive income:
Net income	193,173			193,173
Changes in net prior service credit and actuarial losses, net of tax provision of $8,435 in 2009, tax benefit of $654 in 2010, and tax benefit of $16,045 in 2011	(25,602)				(25,602)
Change in fair value of derivatives, net of tax benefit of $664 in 2009, tax provision of $882 in 2010, and tax benefit of $65 in 2011	(127)				(127)
Foreign currency translation, net of tax provision of $1,272 in 2009, $6,248 in 2010, and $6,469 in 2011	(26,527)				(26,527)
Comprehensive income	140,917
Dividends declared on common stock	(31,109)			(31,109)
Stock compensation expense	7,692		7,692
Stock option exercises, including tax benefit of $3,413 in 2009, $2,952 in 2010, and $2,576 in 2011 (in shares)	217,360	217,000
Stock option exercises, including tax benefit of $3,413 in 2009, $2,952 in 2010, and $2,576 in 2011	4,451	2	4,449
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $282 in 2009, $408 in 2010, and $1,856 in 2011 (in shares)		232,000
Net issuance of treasury stock for vested restricted stock units, including tax benefit of $282 in 2009, $408 in 2010, and $1,856 in 2011	(3,341)		(621)			(2,720)
Repurchases of common stock (in shares)	(441,416)	(441,416)
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