Financial Statement Components - Components of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 260,040	$ 188,277
Less: accumulated depreciation and amortization	(127,073)	(99,047)
Property and equipment, net	132,967	89,230
Computer hardware and software
Property, Plant and Equipment [Line Items]
Total property and equipment	159,970	120,841
Internal-use software development costs
Property, Plant and Equipment [Line Items]
Total property and equipment	79,277	48,419
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	8,131	7,690
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 12,662	$ 11,327