Leases - Lessee, Operating Lease Other Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Operating cash flows from operating leases	$ (5,921)	$ (5,242)	$ (17,322)	$ (14,551)
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 1,076	$ 6,155	$ 21,319	$ 29,262
Weighted-average remaining lease term of operating leases	7 years 6 months	7 years 9 months 18 days	7 years 6 months	7 years 9 months 18 days
Weighted-average discount rate of operating leases	3.30%	3.70%	3.30%	3.70%