Consolidated Statements of Shareholders' Equity - USD ($)	Total	Common Stock Including Additional Paid in Capital [Member]	Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	Accumulated Defined Benefit Plans Adjustment [Member]	Accumulated Translation Adjustment [Member]	Retained Earnings [Member]
Share balance at Dec. 31, 2013		27,155,550
Balance at Dec. 31, 2013	$ 483,063,000	$ 75,305,000		$ (2,258,000)	$ (58,105,000)	$ 468,121,000
Net Income	8,803,000					8,803,000
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(4,765,000)		$ (4,765,000)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	(2,928,000)			(2,928,000)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(13,369,000)				(13,369,000)
Exercised		453,745
Stock Options Exercised, Value	7,423,000	$ 7,423,000
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures		210,512
Stock Based Compensation Expense	2,315,000	$ 2,315,000
Tax Impact of Stock Options	(416,000)	$ 416,000
Stock Repurchased and Retired During Period, Shares		(1,089,560)
Stock Repurchased and Retired During Period, Value	(21,790,000)	$ (3,154,000)				(18,636,000)
Cash Dividends Declared	(19,330,000)					(19,330,000)
Share balance at Dec. 31, 2014		26,730,247
Balance at Dec. 31, 2014	439,006,000	$ 81,473,000	(4,765,000)	(5,186,000)	(71,474,000)	438,958,000
Net Income	23,944,000					23,944,000
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(4,524,000)		(4,524,000)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	1,046,000			1,046,000
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(16,810,000)				(16,810,000)
Exercised		420,642
Stock Options Exercised, Value	7,265,000	$ 7,265,000
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures		4,960
Stock Based Compensation Expense	2,807,000	$ 2,807,000
Tax Impact of Stock Options	0	$ 0
Stock Repurchased and Retired During Period, Shares		(1,056,954)
Stock Repurchased and Retired During Period, Value	(19,638,000)	$ (3,437,000)				(16,201,000)
Cash Dividends Declared	(19,184,000)					(19,184,000)
Share balance at Dec. 31, 2015		26,098,895
Balance at Dec. 31, 2015	413,912,000	$ 88,108,000	(9,289,000)	(4,140,000)	(88,284,000)	427,517,000
Net Income	41,381,000					41,381,000
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(6,812,000)		(6,812,000)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	504,000			504,000
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(16,904,000)				(16,904,000)
Exercised		86,908
Stock Options Exercised, Value	1,641,000	$ 1,641,000
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures		(1,165)
Stock Based Compensation Expense	3,618,000	$ 3,618,000
Tax Impact of Stock Options	(92,000)	$ (92,000)
Stock Repurchased and Retired During Period, Shares		(1,040,688)
Stock Repurchased and Retired During Period, Value	(20,719,000)	$ (3,543,000)				(17,176,000)
Cash Dividends Declared	(18,487,000)					(18,487,000)
Share balance at Dec. 31, 2016		25,143,950
Balance at Dec. 31, 2016	$ 398,226,000	$ 89,916,000	$ (16,101,000)	$ (3,636,000)	$ (105,188,000)	$ 433,235,000