Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total	$ 61,872		$ 61,872		$ 44,557
Less: accumulated depreciation and amortization	(21,912)		(21,912)		(17,710)
Property and equipment, net	39,960		39,960		26,847
Depreciation and amortization	2,100	$ 1,400	6,100	$ 4,200
Computer software and equipment
Property, Plant and Equipment [Line Items]
Total	23,327		23,327		21,234
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total	7,023		7,023		4,504
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total	29,951		29,951		16,953
Right-of-use assets under finance leases
Property, Plant and Equipment [Line Items]
Total	$ 1,571		$ 1,571		$ 1,866