INCOME (LOSS) PER COMMON SHARE - Calculations of Basic and Diluted Loss per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income (loss)	$ 5,789	$ 3,067	$ (3,977)	$ (28,164)	$ 8,856	$ (32,141)
Weighted-average shares outstanding - Basic (in shares)	21,322		20,824		21,239	20,784
Effect of dilutive securities:
Weighted-average shares outstanding - Basic and Diluted (in shares)	21,965		20,824		21,903	20,784
Basic income (loss) per common share (usd per share)	$ 0.27		$ (0.19)		$ 0.42	$ (1.55)
Diluted income (loss) per common share (usd per share)	$ 0.26		$ (0.19)		$ 0.40	$ (1.55)
Antidilutive securities (in shares)	423		2,088		422	2,100
Stock options and other stock awards
Effect of dilutive securities:
Stock options and other stock awards (in shares)	643		0		664	0