COMMITMENTS AND CONTINGENCIES - Narrative (Details) $ in Thousands					1 Months Ended		12 Months Ended
	Jan. 08, 2019 defendant	Jul. 16, 2018 USD ($)	Apr. 02, 2018 USD ($)	Mar. 29, 2016 plaintiff	Jan. 31, 2016 claim	May 31, 2013 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Rent expense for operating leases							$ 2,200	$ 2,000
Number of days to provide notification to terminate purchase commitment agreement						90 days
Minimum monthly purchase amount						$ 40
Employment Agreements
Loss Contingencies [Line Items]
Number of weeks (months) to provide notice of termination of agreement by either party							1 month
Securities Class Actions
Loss Contingencies [Line Items]
Number of complaints filed | claim					2
Number of lead plaintiffs named | plaintiff				2
Litigation settlement amount			$ 1,750
Securities Class Actions | Subsequent Event | Executive Officers
Loss Contingencies [Line Items]
Number of parties named in putative securities class action suit | defendant	2
Shareholder Derivative Claims
Loss Contingencies [Line Items]
Litigation settlement amount		$ 250