INCOME TAXES - Valuation Allowances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation allowance, additions	$ 11,166	$ 49,582	$ 48,501
Valuation allowance, deductions	(1,151)	(15,165)	(14,870)
Valuation Allowance of Deferred Tax Assets
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation allowances, beginning balance	153,651	119,234	85,603
Valuation Allowances, ending balance	$ 163,666	$ 153,651	$ 119,234