SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Right of use lease assets, net	$ 12,648	$ 12,600	$ 0
Lease liability	13,037	$ 12,900
Transaction price allocated to unsatisfied performance obligation	3,800
Unearned revenues	3,100		$ 1,700
Revenues recognized that was included in the deferred revenue balance	$ 1,100