Balance Sheet Components, Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Property and Equipment, Net [Abstract]
Less: Accumulated depreciation	$ (20,574)	$ (17,732)
Total	6,677	7,145
Computer hardware (useful life of 3 years)
Property and Equipment, Net [Abstract]
Property, Plant and Equipment, Gross	$ 14,160	13,110
Useful life	3 years
Furniture and fixtures (useful life of 5 years)
Property and Equipment, Net [Abstract]
Property, Plant and Equipment, Gross	$ 4,653	3,772
Useful life	5 years
Leasehold improvements (useful life of 5 years)
Property and Equipment, Net [Abstract]
Property, Plant and Equipment, Gross	$ 3,396	2,836
Useful life	5 years
Software (useful life of 1 to 7 years)
Property and Equipment, Net [Abstract]
Property, Plant and Equipment, Gross	$ 5,042	$ 5,159
Minimum
Property and Equipment, Net [Abstract]
Useful life	1 year
Minimum \| Software (useful life of 1 to 7 years)
Property and Equipment, Net [Abstract]
Useful life	1 year
Maximum
Property and Equipment, Net [Abstract]
Useful life	7 years
Maximum \| Software (useful life of 1 to 7 years)
Property and Equipment, Net [Abstract]
Useful life	7 years

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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