Comprehensive Income (Loss) - Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Comprehensive Income (Loss)
Net earnings	$ (5,869)	$ 6,585	$ (13,590)	$ 12,067
Foreign currency translation adjustments	751	(711)	(217)	(481)
Pension liability, net of tax of $49, $40, $149 and $122, respectively	142	116	424	347
Comprehensive income (loss)	$ (4,976)	$ 5,990	$ (13,383)	$ 11,933