SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Net income (loss)	$ 96,831	$ 63,116	$ 65,584
Weighted average common shares, basic (in shares)	49,274	48,168	48,060
Weighted average common shares, dilutive (in shares)	49,274	48,168	48,060
Earnings per share—basic (in dollars per share)	$ 1.97	$ 1.31	$ 1.36
Earnings per share—diluted (in dollars per share)	$ 1.97	$ 1.31	$ 1.36