Balance Sheet Components (Schedule of Property and Equipment, Net) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Total property and equipment, gross	$ 119,388	$ 116,108
Accumulated depreciation and amortization	(98,743)	(95,931)
Total property and equipment, net	20,645	20,177
Computer equipment
Total property and equipment, gross	9,814	9,205
Furniture, fixtures and leasehold improvements
Total property and equipment, gross	18,477	18,286
Software
Total property and equipment, gross	28,848	28,065
Machinery and equipment
Total property and equipment, gross	$ 62,249	$ 60,552