ACQUISITIONS (Details) - USD ($) $ in Thousands			12 Months Ended
		Apr. 11, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Purchase price of acquired company	[1]		$ 800	$ 297	$ 49,113
OpenSpan, Inc.
Business Acquisition [Line Items]
Purchase price of acquired company		$ 48,800
Cash acquired from acquisition		$ 1,800

[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.