Equity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Stockholders Equity Note [Line Items]
Balance, December 31, 2014			$ 197,954
Net earnings	$ 5,377	$ 5,545	11,054	$ 11,296
Foreign currency translation adjustments	(1,609)	$ (1,426)	(3,109)	$ (796)
Pension liability adjustment, net of tax			815
Balance, September 30, 2015	199,818		199,818
Common Stock [Member]
Stockholders Equity Note [Line Items]
Balance, December 31, 2014			10,821
Net earnings			0
Foreign currency translation adjustments			0
Pension liability adjustment, net of tax			0
Cash dividends declared			0
Stock options exercised			138
Issuance of restricted stock			22
Stock-based compensation expense			0
Income tax benefit from stock options exercised			0
Shares purchased and retired			(172)
Balance, September 30, 2015	10,809		10,809
Capital in Excess of Par Value [Member]
Stockholders Equity Note [Line Items]
Balance, December 31, 2014			37,966
Net earnings			0
Foreign currency translation adjustments			0
Pension liability adjustment, net of tax			0
Cash dividends declared			0
Stock options exercised			2,558
Issuance of restricted stock			(22)
Stock-based compensation expense			1,112
Income tax benefit from stock options exercised			461
Shares purchased and retired			0
Balance, September 30, 2015	42,075		42,075
Reinvested Earnings [Member]
Stockholders Equity Note [Line Items]
Balance, December 31, 2014			160,179
Net earnings			11,199
Foreign currency translation adjustments			0
Pension liability adjustment, net of tax			0
Cash dividends declared			(6,405)
Stock options exercised			0
Issuance of restricted stock			0
Stock-based compensation expense			0
Income tax benefit from stock options exercised			0
Shares purchased and retired			(4,588)
Balance, September 30, 2015	160,385		160,385
AOCI Attributable to Parent [Member]
Stockholders Equity Note [Line Items]
Balance, December 31, 2014			(18,030)
Net earnings			0
Foreign currency translation adjustments			(2,408)
Pension liability adjustment, net of tax			815
Cash dividends declared			0
Stock options exercised			0
Issuance of restricted stock			0
Stock-based compensation expense			0
Income tax benefit from stock options exercised			0
Shares purchased and retired			0
Balance, September 30, 2015	(19,623)		(19,623)
Noncontrolling Interest [Member]
Stockholders Equity Note [Line Items]
Balance, December 31, 2014			7,018
Net earnings			(145)
Foreign currency translation adjustments			(701)
Pension liability adjustment, net of tax			0
Cash dividends declared			0
Stock options exercised			0
Issuance of restricted stock			0
Stock-based compensation expense			0
Income tax benefit from stock options exercised			0
Shares purchased and retired			0
Balance, September 30, 2015	$ 6,172		$ 6,172