SIGNIFICANT ACCOUNTING POLICIES - Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Numerator:
Net income (loss) as reported	$ 15,170	$ 3,920
Less: Distributed net income available to participating securities	(6)	(8)
Less: Undistributed net income available to participating securities	(312)	(94)
Numerator for basic net income per share	14,852	3,818
Add: Undistributed net income allocated to participating securities	312	94
Less: Undistributed net income reallocated to participating securities	(311)	(94)
Numerator for diluted net income per share	$ 14,853	$ 3,818
Denominator:
Weighted average shares outstanding for basic net income per share (in shares)	14,606,052	14,449,915
Effect of dilutive securities (in shares)	65,637	0
Weighted average shares outstanding for diluted net income per share (in shares)	14,671,689	14,449,915
Net income (loss) allocated to common stock for EPS calculation:
Basic (in dollars per share)	$ 1.02	$ 0.26
Diluted (in dollars per share)	$ 1.01	$ 0.26