COMPONENTS OF THE COMPANY'S CONDENSED CONSOLIDATED BALANCE SHEETS Intangible Assets (Details) - USD ($) $ in Thousands		Jun. 30, 2019	Dec. 31, 2018
Schedule of Intangible Assets [Table] [Line Items]
Intangible Assets, Gross		$ 60,502	$ 60,251
Finite-Lived Intangible Assets, Accumulated Amortization		(41,582)	(39,099)
Total		18,920	21,152
Finite-Lived Intangible Assets, Net	[1]	12,969
Developed technology
Schedule of Intangible Assets [Table] [Line Items]
Finite-Lived Intangible Assets, Gross		33,270	33,270
Finite-Lived Intangible Assets, Accumulated Amortization		(24,052)	(22,464)
Finite-Lived Intangible Assets, Net		9,218	10,806
Customer relationships
Schedule of Intangible Assets [Table] [Line Items]
Finite-Lived Intangible Assets, Gross		20,030	20,030
Finite-Lived Intangible Assets, Accumulated Amortization		(17,342)	(16,520)
Finite-Lived Intangible Assets, Net		2,688	3,510
Technology licenses
Schedule of Intangible Assets [Table] [Line Items]
Finite-Lived Intangible Assets, Gross		1,251	1,000
Finite-Lived Intangible Assets, Accumulated Amortization		(188)	(115)
Finite-Lived Intangible Assets, Net		1,063	885
Internet Domain Names [Member]
Schedule of Intangible Assets [Table] [Line Items]
Indefinite-Lived Intangible Assets		1,261	1,261
In-process research and development
Schedule of Intangible Assets [Table] [Line Items]
Indefinite-Lived Intangible Assets		$ 4,690	$ 4,690

[1] The total above excludes $4.7 million of in-process research and development that will be amortized, upon completion of development, over the estimated useful life of the technology.