Property and Equipment - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Accumulated depreciation and amortization	$ (59,766)	$ (41,614)
Property and equipment, net	$ 58,671	43,988
Minimum
Property, Plant and Equipment [Line Items]
Useful Lives (years)	2 years
Maximum
Property, Plant and Equipment [Line Items]
Useful Lives (years)	3 years
Property and equipment, gross
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 108,072	79,909
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	33,455	29,558
Website and software development costs
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 50,439	33,278
Website and software development costs | Minimum
Property, Plant and Equipment [Line Items]
Useful Lives (years)	2 years
Website and software development costs | Maximum
Property, Plant and Equipment [Line Items]
Useful Lives (years)	3 years
Computer and office equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 14,216	7,765
Computer and office equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful Lives (years)	3 years
Computer and office equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful Lives (years)	5 years
Software
Property, Plant and Equipment [Line Items]
Useful Lives (years)	3 years
Property and equipment, gross	$ 1,871	1,858
Furniture
Property, Plant and Equipment [Line Items]
Useful Lives (years)	7 years
Property and equipment, gross	$ 8,091	7,450
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 10,365	$ 5,693