EARNINGS PER SHARE (''EPS'') - Reconciliation of the Numerator and Denominator Used in Computing Basic and Diluted Per Share Computations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net loss attributable to common stockholders	$ (8,206)	$ (6,787)
Redeemable preferred stock dividends declared on dilutive shares	0	(1)
Diluted net loss attributable to common stockholders	$ (8,206)	$ (6,788)
Denominator:
Basic weighted average shares outstanding (in shares)	14,808,000	14,598,000
Diluted weighted average shares and common stock equivalents outstanding (in shares)	14,808,000	14,599,000
Net loss attributable to common stockholders per share:
Basic (in usd per share)	$ (0.55)	$ (0.46)
Diluted (in usd per share)	$ (0.55)	$ (0.46)
Series A Preferred Stock
Denominator:
Effect of dilutive securities—contingently issuable shares (in shares)	0	1,000