BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES - Gain on Litigation Settlement (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accounting Policies [Abstract]
Gain (loss) on litigation settlement	$ 6,286,000	$ 0	$ 6,286,000	$ 0
Cash received from gain on litigation settlement	4,000,000.0
Cash receivable from gain on litigation settlement	937,000
Liabilities waived due to litigation settlement	$ 1,400,000