Property and Equipment, Net - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Subtotal	$ 178,768	$ 132,997
Less: accumulated depreciation and amortization	(92,895)	(68,809)
Property and equipment, net	85,873	64,188
Equipment
Property, Plant and Equipment [Line Items]
Subtotal	$ 73,234	49,633
Equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	1 year
Equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	13 years
Building
Property, Plant and Equipment [Line Items]
Subtotal	$ 7,400	7,400
Estimated Useful Lives in Years	40 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Subtotal	$ 27,688	23,683
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	1 year
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	17 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Subtotal	$ 7,425	5,858
Furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	1 year
Furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	9 years
Computer hardware and office equipment
Property, Plant and Equipment [Line Items]
Subtotal	$ 22,843	15,280
Computer hardware and office equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	1 year
Computer hardware and office equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	10 years
Computer software
Property, Plant and Equipment [Line Items]
Subtotal	$ 30,718	20,806
Computer software | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	1 year
Computer software | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	10 years
Land
Property, Plant and Equipment [Line Items]
Subtotal	$ 3,170	3,170
Construction in progress
Property, Plant and Equipment [Line Items]
Subtotal	$ 6,290	$ 7,167