Consolidated Statement of Shareholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulative Other Comprehensive Income (Loss) [Member]	Retained Income (Deficit) [Member]
Balance at Dec. 31, 2011	$ 206,140	$ 20,312	$ 265,000	$ 7,294	$ (86,466)
Balance, shares at Dec. 31, 2011		33,420,488
Stockholders' Equity [Roll Forward]
Net income	29,962				29,962
Sales under option plans, shares	288,794	278,659
Sales under option plans	3,015	145	2,870
Dividend reinvestment plan, shares		7,112
Dividend reinvestment plan	107	5	102
Restricted stock vested, shares		40,500
Restricted stock award	0	24	(24)
Restricted stock and stock option grants, net (shares)		11,484
Restricted stock and stock option grants, net	2,708		2,708
Tax benefit from options	253		253
Foreign currency translation adjustment	2,791			2,791
Purchase for treasury, shares		(281,797)
Purchases for treasury	(4,204)	(172)	(4,032)
Stock contribution, shares		3,743
Stock contribution	50	2	48
Declared dividends	(10,852)				(10,852)
Pension liability, net of tax	558			558
Balance at Dec. 31, 2012	230,022	20,316	266,419	10,643	(67,356)
Balance, shares at Dec. 31, 2012		33,480,189
Stockholders' Equity [Roll Forward]
Net income	26,002				26,002
Sales under option plans, shares	503,321	503,321
Sales under option plans	5,693	299	5,394
Dividend reinvestment plan, shares		7,390
Dividend reinvestment plan	113	4	109
Restricted stock vested, shares		112,000
Restricted stock award	0	0	0
Restricted stock and stock option grants, net (shares)		33,152
Restricted stock and stock option grants, net	2,237		2,237
Tax benefit from options	389		389
Foreign currency translation adjustment	(9,292)			(9,292)
Purchase for treasury, shares		(530,983)
Purchases for treasury	(8,096)	(314)	(7,782)
Stock contribution, shares		12,682
Stock contribution	202	8	194
Shares withheld for employee taxes on equity awards, shares		(44,973)
Shares withheld for employee taxes on equity awards	(684)		(684)
Declared dividends	(12,155)				(12,155)
Pension liability, net of tax	1,076			1,076
Balance at Dec. 31, 2013	235,507	20,313	266,276	2,427	(53,509)
Balance, shares at Dec. 31, 2013		33,572,778
Stockholders' Equity [Roll Forward]
Net income	(8,681)				(8,681)
Sales under option plans, shares	228,064	227,664
Sales under option plans	2,792	138	2,654
Dividend reinvestment plan, shares		7,159
Dividend reinvestment plan	134	4	130
Restricted stock vested, shares		123,829
Restricted stock award	0	75	(75)
Restricted stock and stock option grants, net (shares)		15,055
Restricted stock and stock option grants, net	2,835	10	2,825
Tax benefit from options	679		679
Foreign currency translation adjustment	(13,318)			(13,318)
Purchase for treasury, shares		(2,742,506)
Purchases for treasury	(54,897)	(1,660)	(53,237)
Stock contribution, shares		9,376
Stock contribution	200	6	194
Shares withheld for employee taxes on equity awards, shares		(50,393)
Shares withheld for employee taxes on equity awards	(1,083)	(31)	(1,052)
Declared dividends	(16,800)				(16,800)
Pension liability, net of tax	(797)			(797)
Balance at Dec. 31, 2014	$ 146,571	$ 18,855	$ 218,394	$ (11,688)	$ (78,990)
Balance, shares at Dec. 31, 2014		31,162,962