INCOME TAXES - Valuation Allowances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation allowance, Beginning Balance	$ 135,764
Valuation allowance, additions	11,459	$ 7,469
Valuation allowance, deductions	(15,669)	(1,800)
Valuation allowance, Ending Balance	131,554	135,764
Valuation Allowance of Deferred Tax Assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation allowance, Beginning Balance	135,764	130,095
Valuation allowance, Ending Balance	$ 131,554	$ 135,764