Leases - Additional Information (Detail) $ in Thousands	1 Months Ended	12 Months Ended
	Sep. 30, 2019 USD ($) ft²	Dec. 31, 2019 USD ($) Agreement
Lessee Lease Description [Line Items]
Operating lease, option to extend		Certain leases contain options to extend the initial term at the Company’s discretion
Operating lease, existence of option to extend [true false]		true
Weighted average remaining lease term		13 years 3 months 18 days
Weighted average discount rate		5.90%
Area of square feet for office space | ft²	15,646
Lease commencement date	Dec. 01, 2019
Lease expiration date	Jan. 15, 2027
Aggregate minimum rental commitment amount	$ 8,300
Operating lease right-of-use assets		$ 81,399
Operating lease liabilities		$ 97,991
Number of lease agreements assigned to third parties | Agreement		2
Future lease obligation under sublease arrangements		$ 3,800
Property One [Member]
Lessee Lease Description [Line Items]
Lease termination dates		2020-11
Property Two [Member]
Lessee Lease Description [Line Items]
Lease termination dates		2022-02
Office Space [Member]
Lessee Lease Description [Line Items]
Operating lease right-of-use assets	7,000
Operating lease liabilities	$ 7,000
Minimum [Member]
Lessee Lease Description [Line Items]
Term of lease contract		1 year
Maximum [Member]
Lessee Lease Description [Line Items]
Term of lease contract		15 years