CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) [Abstract]
Net income (loss)	$ 4,489	$ (1,750)
Other comprehensive income (loss)
Derivative qualifying as a cash flow hedge, net of taxes (nil)	211	(748)
Employee pension plan adjustments, net of taxes (nil)	(134)	140
Comprehensive income (loss)	$ 4,566	$ (2,358)