Balance Sheet Components (Schedule Of Intangibles, Net) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Purchased Intangible Assets [Line Items]
Gross	$ 134,144	$ 134,144
Accumulated Amortization	(109,156)	(96,245)
Finite-lived intangibles, net	24,988	37,899
Technology [Member]
Purchased Intangible Assets [Line Items]
Gross	66,599	66,599
Accumulated Amortization	(62,172)	(57,381)
Finite-lived intangibles, net	4,427	9,218
Customer Contracts And Relationships [Member]
Purchased Intangible Assets [Line Items]
Gross	56,500	56,500
Accumulated Amortization	(37,430)	(30,375)
Finite-lived intangibles, net	19,070	26,125
Other [Member]
Purchased Intangible Assets [Line Items]
Gross	11,045	11,045
Accumulated Amortization	(9,554)	(8,489)
Finite-lived intangibles, net	$ 1,491	$ 2,556