Comprehensive Income - Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Comprehensive Income
Net earnings	$ 6,585	$ 6,152	$ 12,067	$ 10,491
Foreign currency translation adjustments	(711)	(182)	(481)	(1,292)
Pension liability, net of tax of $40, $41, $122 and $124, respectively	116	116	347	352
Total comprehensive income	$ 5,990	$ 6,086	$ 11,933	$ 9,551