LEASES - Narrative, Lease Term and Discount Rate (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Leases [Abstract]
Operating lease cost	$ 1.8	$ 3.7
Weighted-average remaining lease term, operating leases	5 years 3 months 1 day	5 years 3 months 1 day
Weighted-average discount rate, operating leases	10.97%	10.97%