SUBSEQUENT EVENTS (UNAUDITED) - Additional Information (Details) - USD ($)	1 Months Ended
	Jan. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Subsequent Event [Line Items]
Tax credits receivable net of allowance		$ 53,000,000	$ 53,000,000
Subsequent Event
Subsequent Event [Line Items]
Cash proceeds from sale of assets	$ 500,000
License fees	15,000,000
Tax credits receivable, net	2,700,000
Tax credits receivable net of allowance	27,700,000
Subsequent Event | Sellers’ Agreement
Subsequent Event [Line Items]
Cash proceeds from sale of assets	14,500,000
Subsequent Event | Sellers’ Agreement | Maximum
Subsequent Event [Line Items]
Earnout payment receivable	$ 5,000,000