Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Property and equipment, gross		$ 16,737	$ 15,166
Less accumulated depreciation and amortization		(8,236)	(7,392)
Property and equipment, net		8,501	7,774
Furniture and Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross		$ 2,044	2,041
Property and equipment, useful life in years		5 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross		$ 4,957	4,944
Property and equipment, useful life in years	[1]	9 years
Systems Hardware
Property Plant And Equipment [Line Items]
Property and equipment, gross		$ 812	807
Property and equipment, useful life in years		5 years
Office Computers
Property Plant And Equipment [Line Items]
Property and equipment, gross		$ 6,856	6,547
Property and equipment, useful life in years		3 years
Computer and System Software
Property Plant And Equipment [Line Items]
Property and equipment, gross		$ 2,068	$ 827
Property and equipment, useful life in years		3 years

[1] Lesser of the lease term or the estimated useful lives of the improvements, which may be up to 9 years.