SIGNIFICANT ACCOUNTING POLICIES - Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator:
Net (loss) income as reported	$ (5,648)	$ 17,244	$ (1,493)	$ 32,414
Less: Distributed net income available to participating securities	0	(2)	0	(5)
Less: Undistributed net income available to participating securities	0	(136)	0	(256)
Numerator for basic net (loss) income per share:	(5,648)	17,106	(1,493)	32,153
Add: Undistributed net income allocated to participating securities	0	136	0	256
Less: Undistributed net income reallocated to participating securities	0	(134)	0	(252)
Numerator for diluted net (loss) income per share:	$ (5,648)	$ 17,108	$ (1,493)	$ 32,157
Denominator:
Weighted average shares outstanding for basic net (loss) income per share (in shares)	14,832,242	14,647,019	14,745,661	14,624,718
Effect of dilutive securities (in shares)	0	252,968	0	225,098
Weighted average shares outstanding for diluted net (loss) income per share (in shares)	14,832,242	14,899,987	14,745,661	14,849,816
Net (loss) income per share:
Basic (in dollars per share)	$ (0.38)	$ 1.17	$ (0.10)	$ 2.20
Diluted (in dollars per share)	$ (0.38)	$ 1.15	$ (0.10)	$ 2.17
Anti-dilutive securities (in shares)	30,967		35,742