PROPERTY AND EQUIPMENT, NET - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciation expense		$ 1,200	$ 4,700	$ 2,000
Accelerated depreciation, related to leasehold improvements			2,700
Property plant and equipment disposals	$ 9,600
Loss (gain) on disposal of equipment	10,100	$ 10,076	$ 669	$ (271)
Selling, general and administrative expense
Property, Plant and Equipment [Line Items]
Loss (gain) on disposal of equipment	$ 500