Property and Equipment, Net - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Subtotal	$ 132,997	$ 111,015
Less: accumulated depreciation and amortization	(68,809)	(50,127)
Property and equipment, net	64,188	60,888
Equipment
Property, Plant and Equipment [Line Items]
Subtotal	$ 49,633	43,164
Equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	3 years
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	$ 23,683	22,207
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	2 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	20 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Subtotal	$ 5,858	5,675
Furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	5 years
Furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	10 years
Computer hardware and office equipment
Property, Plant and Equipment [Line Items]
Subtotal	$ 15,280	12,137
Computer hardware and office equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	3 years
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	$ 20,806	14,341
Computer software | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives in Years	2 years
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
Assets not yet placed in service
Property, Plant and Equipment [Line Items]
Subtotal	$ 7,167	$ 2,921