DEFERRED CONTRACT COSTS - Schedule of Amortization of Deferred Contract Costs (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Amortization of deferred contract costs	[1]	$ 17,271	$ 12,106	$ 11,574

[1] On January 1, 2018, the Company adopted the ASC 606 revenue recognition standard and adjusted prior periods to conform. See "Note 2. Significant Accounting Policies" for additional information.