Balance Sheet Components - Components of Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 62,082	$ 60,217
Less: Accumulated depreciation and amortization	(53,558)	(48,402)
Property and equipment, net	8,524	11,815
Computer Equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 22,424	22,714
Computer Equipment [Member] \| Minimum [Member]
Property Plant And Equipment [Line Items]
Estimated useful life	3 years
Computer Equipment [Member] \| Maximum [Member]
Property Plant And Equipment [Line Items]
Estimated useful life	4 years
Software, Including Internally Developed Software [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 27,974	25,518
Estimated useful life	3 years
Finance Lease ROU Assets [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 5,067	5,067
Estimated useful life	4 years
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 4,631	4,778
Office Equipment, Furniture and Fixtures [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 1,986	$ 2,140
Office Equipment, Furniture and Fixtures [Member] \| Minimum [Member]
Property Plant And Equipment [Line Items]
Estimated useful life	3 years
Office Equipment, Furniture and Fixtures [Member] \| Maximum [Member]
Property Plant And Equipment [Line Items]
Estimated useful life	5 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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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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