Equity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Balance	$ 187,925
Net earnings	1,325	$ 1,162
Foreign currency translation adjustments	(143)	(2,558)
Pension liability adjustment, net of tax	183
Balance	186,420
Common Stock
Balance	9,797	9,873
Net earnings	0	0
Foreign currency translation adjustments	0	0
Pension liability adjustment, net of tax	0	0
Cash dividends declared	0	0
Share-based compensation expense	0	0
Shares purchased and retired	(62)	(60)
Balance	9,735	9,813
Capital in Excess of Par Value
Balance	67,178	65,832
Net earnings	0	0
Foreign currency translation adjustments	0	0
Pension liability adjustment, net of tax	0	0
Cash dividends declared	0	0
Share-based compensation expense	545	351
Shares purchased and retired	0	0
Balance	67,723	66,183
Reinvested Earnings
Balance	138,955	158,825
Net earnings	1,325	1,162
Foreign currency translation adjustments	0	0
Pension liability adjustment, net of tax	0	0
Cash dividends declared	(2,336)	(2,357)
Share-based compensation expense	0	0
Shares purchased and retired	(1,017)	(1,244)
Balance	136,927	156,386
Accumulated Other Comprehensive Loss
Balance	(28,005)	(24,536)
Net earnings	0	0
Foreign currency translation adjustments	(143)	(2,558)
Pension liability adjustment, net of tax	183	138
Cash dividends declared	0	0
Share-based compensation expense	0	0
Shares purchased and retired	0	0
Balance	$ (27,965)	$ (26,956)