Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property Plant And Equipment [Line Items]
Total property and equipment	$ 44,944	$ 27,516
Accumulated depreciation and amortization	(19,680)	(12,780)
Property and Equipment, net	25,264	14,736
Computer and Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	16,056	11,631
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	18,396	8,437
Website and Internal-Use Software
Property Plant And Equipment [Line Items]
Total property and equipment	6,423	5,461
Office Equipment and Furniture
Property Plant And Equipment [Line Items]
Total property and equipment	$ 4,069	$ 1,987

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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