Equity (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Stockholders Equity Note [Line Items]
Beginning Balance			$ 196,992
Net earnings	5,545	5,601	11,296	10,991
Foreign currency translation adjustments	(1,426)	470	(796)	(1,557)
Pension liability adjustment, net of tax	107	269	323	770
Ending Balance	199,899		199,899
Common Stock [Member]
Stockholders Equity Note [Line Items]
Beginning Balance			10,876
Net earnings			0
Foreign currency translation adjustments			0
Pension liability adjustment, net of tax			0
Cash dividends declared			0
Cash dividends declared to noncontrolling interest			0
Stock options exercised			59
Issuance of restricted stock			24
Stock-based compensation expense			0
Income tax benefit from stock options exercised			0
Shares purchased and retired			(153)
Ending Balance	10,806		10,806
Capital in Excess of Par Value [Member]
Stockholders Equity Note [Line Items]
Beginning Balance			31,729
Net earnings			0
Foreign currency translation adjustments			0
Pension liability adjustment, net of tax			0
Cash dividends declared			0
Cash dividends declared to noncontrolling interest			0
Stock options exercised			1,167
Issuance of restricted stock			(24)
Stock-based compensation expense			1,046
Income tax benefit from stock options exercised			85
Shares purchased and retired			0
Ending Balance	34,003		34,003
Reinvested Earnings [Member]
Stockholders Equity Note [Line Items]
Beginning Balance			156,983
Net earnings			10,930
Foreign currency translation adjustments			0
Pension liability adjustment, net of tax			0
Cash dividends declared			(6,081)
Cash dividends declared to noncontrolling interest			0
Stock options exercised			0
Stock-based compensation expense			0
Income tax benefit from stock options exercised			0
Shares purchased and retired			(3,843)
Ending Balance	157,989		157,989
Accumulated Other Comprehensive Income (Loss) [Member]
Stockholders Equity Note [Line Items]
Beginning Balance			(9,422)
Net earnings			0
Foreign currency translation adjustments			(665)
Pension liability adjustment, net of tax			323
Cash dividends declared			0
Cash dividends declared to noncontrolling interest			0
Stock options exercised			0
Stock-based compensation expense			0
Income tax benefit from stock options exercised			0
Shares purchased and retired			0
Ending Balance	(9,764)		(9,764)
Noncontrolling Interest [Member]
Stockholders Equity Note [Line Items]
Beginning Balance			6,826
Net earnings			366
Foreign currency translation adjustments			(131)
Pension liability adjustment, net of tax			0
Cash dividends declared			0
Cash dividends declared to noncontrolling interest			(196)
Stock options exercised			0
Stock-based compensation expense			0
Income tax benefit from stock options exercised			0
Shares purchased and retired			0
Ending Balance	$ 6,865		$ 6,865