CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 1,655	$ (1,270)	$ 5,607	$ (13,420)	$ (7,230)
Other comprehensive income (loss), net of tax:
Change in foreign currency translation adjustments	84	47	(117)	(214)	(304)
Pension benefit plan	13	(662)	(648)	(743)	(1,063)
Total comprehensive income (loss)	$ 1,752	$ (1,885)	$ 4,842	$ (14,377)	$ (8,597)