INCOME TAXES - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax [Line Items]
Tax credit carryforward	$ 400
Valuation allowance	173,841	$ 142,749	$ 132,712	$ 164,865
Undistributed earnings of foreign subsidiaries	100
Unrecognized tax positions	1	300	$ 162
Interest and penalties accrued	100	$ 200
U.S. Tax Authority
Income Tax [Line Items]
Net operating loss carryforwards	341,200
Valuation allowance	166,600
Unrecognized tax positions	190,700
Foreign Tax Authority
Income Tax [Line Items]
Net operating loss carryforwards	46,600
Valuation allowance	7,200
Tax Years 2018 to 2037 | U.S. Tax Authority
Income Tax [Line Items]
Net operating loss carryforwards	285,200
No Expiration Date | U.S. Tax Authority
Income Tax [Line Items]
Net operating loss carryforwards	56,000
Her Majesty's Revenue and Customs (HMRC)
Income Tax [Line Items]
Net operating loss carryforwards	14,300
Canada Revenue Agency
Income Tax [Line Items]
Net operating loss carryforwards	9,800
Quebec Revenue Agency
Income Tax [Line Items]
Net operating loss carryforwards	$ 10,100