Leases - Additional Information (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($) ft² 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 10 months 24 days
Weighted average discount rate	6.00%
Number of lease agreements assigned to third parties | Agreement	2
Future lease obligation under sublease arrangements	$ 4,600
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	$ 7,800
Operating lease right-of-use assets	75,390
Operating lease liabilities	92,031
Office Space [Member]
Lessee Lease Description [Line Items]
Operating lease right-of-use assets	6,700
Operating lease liabilities	$ 6,700
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
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