Consolidated Statements of Shareholders' Equity (USD $) In Thousands, except Share data	Total	Common Stock Including Additional Paid in Capital [Member]	Pension Plans, Defined Benefit [Member]	Accumulated Translation Adjustment [Member]	Retained Earnings [Member]
Balance at Dec. 31, 2009	$ 373,272	$ 56,854	$ (2,004)	$ (54,572)	$ 372,994
Share balance at Dec. 31, 2009		26,668,440
Net Income	51,643				51,643
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	(428)		(428)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	1,282			1,282
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	5,997
Exercised		145,350
Stock Options Exercised, Value	2,448	2,448
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures		40,000
Stock Based Compensation Expense	2,373	2,373
Cash Dividends Declared	(17,108)				(17,108)
Balance at Dec. 31, 2010	413,482	61,675	(2,432)	(53,290)	407,529
Share balance at Dec. 31, 2010		26,853,790
Net Income	67,169				67,169
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	(745)		(745)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(9,133)			(9,133)
Exercised		286,973
Stock Options Exercised, Value	4,546	4,546
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures		23,250
Stock Based Compensation Expense	2,251	2,251
Tax Impact of Stock Options	303	303
Cash Dividends Declared	(17,358)				(17,358)
Balance at Dec. 31, 2011	460,515	68,775	(3,177)	(62,423)	457,340
Share balance at Dec. 31, 2011		27,164,013
Net Income	30,891				30,891
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	(1,853)		(1,853)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	4,839			4,839
Exercised	(98,675)	98,675
Stock Options Exercised, Value	1,530	1,530
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures		32,800
Stock Based Compensation Expense	2,072	2,072
Tax Impact of Stock Options	(558)	(558)
Cash Dividends Declared	(30,531)				(30,531)
Balance at Dec. 31, 2012	$ 466,905	$ 71,819	$ (5,030)	$ (57,584)	$ 457,700
Share balance at Dec. 31, 2012		27,295,488