Balance Sheet Components (Schedule of Intangibles, Net) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Intangible Assets [Line Items]
Gross	$ 126,944	$ 126,944
Accumulated Amortization	(111,886)	(109,798)
Net	15,058	17,146
Technology
Intangible Assets [Line Items]
Gross	59,799	59,799
Accumulated Amortization	(57,085)	(56,978)
Net	2,714	2,821
Customer contracts and relationships
Intangible Assets [Line Items]
Gross	56,800	56,800
Accumulated Amortization	(46,111)	(44,280)
Net	10,689	12,520
Other
Intangible Assets [Line Items]
Gross	10,345	10,345
Accumulated Amortization	(8,690)	(8,540)
Net	$ 1,655	$ 1,805