COMMITMENTS AND CONTINGENCIES - Operating Leases Rent expense (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Operating lease, weighted average remaining lease term	2 years 4 months 24 days
Operating lease costs	$ 190
Variable lease costs	60
Total lease costs	$ 250
Minimum
Operating lease liability (in percent)	4.02%
Maximum
Operating lease liability (in percent)	8.95%