Property and Equipment - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Accumulated depreciation and amortization	$ (88,427)	$ (76,597)
Property and equipment, net	48,405	54,939
Property and equipment, gross
Property, Plant and Equipment [Line Items]
Property and equipment, gross	131,493	124,709
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	29,683	32,262
Website and software development costs
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 72,409	62,963
Website and software development costs | Minimum
Property, Plant and Equipment [Line Items]
Useful Lives (Years)	3 years
Website and software development costs | Maximum
Property, Plant and Equipment [Line Items]
Useful Lives (Years)	5 years
Computer and office equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 19,837	19,702
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	$ 1,868	1,871
Furniture
Property, Plant and Equipment [Line Items]
Useful Lives (Years)	7 years
Property and equipment, gross	$ 7,696	7,911
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 5,339	$ 6,827