Leases - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2020
Lessee, Lease, Description [Line Items]
Lease expense under operating leases	$ 17.9
Minimum
Lessee, Lease, Description [Line Items]
Operating lease term		10 years
Finance lease term		10 years
Maximum
Lessee, Lease, Description [Line Items]
Operating lease term		20 years
Finance lease term		20 years