CONDENSED CONSOLIDATED STOCKHOLDERS' EQUITY STATEMENT (USD $) In Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Component [Member]	Accumulated Other Comprehensive Income (Loss), Pension and Postretirement Benefit Plans [Member]
Beginning balance at Dec. 31, 2012	$ 811,860	$ 503	$ 598,180	$ 461,756	$ (218,014)	$ 28,516	$ (59,081)
Beginning balance, shares at Dec. 31, 2012		50,335			(6,167)
Net income	22,245			22,245
Foreign currency translation	(8,526)					(8,526)
Amortization of pension and other postretirement benefit plan losses, net of $0.7 million tax	1,173						1,173
Exercise of stock options, net of tax withholding forfeitures, shares					383
Exercise of stock options, net of tax withholding forfeitures	3,993		(9,115)		13,108
Conversion of restricted stock units into common stock, net of tax withholding forfeitures, shares					81
Conversion of restricted stock units into common stock, net of tax withholding forfeitures	(2,430)		(3,700)		1,270
Share repurchase program	(31,250)				(31,250)
Share repurchase program, shares					(613)
Share-based compensation	7,645		7,645
Dividends ($0.05 per share)	(2,251)			(2,251)
Ending balance at Mar. 31, 2013	$ 802,459	$ 503	$ 593,010	$ 481,750	$ (234,886)	$ 19,990	$ (57,908)
Ending balance, shares at Mar. 31, 2013		50,335			(6,316)