Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Total property and equipment	$ 234,756	$ 201,277
Accumulated depreciation and amortization	(64,150)	(46,080)
Property and equipment, net	170,606	155,197
Computer and Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	36,825	30,859
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	170,771	144,013
Website and Internal-Use Software
Property Plant And Equipment [Line Items]
Total property and equipment	7,274	6,744
Office Equipment and Furniture
Property Plant And Equipment [Line Items]
Total property and equipment	$ 19,886	$ 19,661