SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
Net (loss) income applicable to common stockholders									$ (5,487)	$ 55,130	$ 72,078
Weighted average shares outstanding, basic (in shares)									31,315,151	37,705,179	36,938,943
Weighted average effect of dilutive securities (in shares)									0	114,438	1,612,765
Weighted average shares outstanding, diluted (in shares)									31,315,151	37,819,617	38,551,708
Per share data
Basic (in dollars per share)	$ 0.62	$ 0.22	$ (0.77)	$ (0.28)	$ 0.40	$ 0.19	$ 0.42	$ 0.46	$ (0.18)	$ 1.46	$ 1.95
Diluted (in dollars per share)	$ 0.61	$ 0.22	$ (0.77)	$ (0.28)	$ 0.40	$ 0.18	$ 0.42	$ 0.46	$ (0.18)	$ 1.46	$ 1.87
Anti-dilutive shares excluded from the calculation of diluted earnings per share (in shares)									4,919,326	3,251	0