Leases - Schedule of Maturity Analysis of Lease Liabilities (Parenthetical) (Detail) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Leases [Abstract]
Operating leases with options to extend lease terms that are reasonably certain of being exercised	$ 0
Legally binding minimum lease payments for leases signed but not yet commenced	64,200,000
Operating leases, current portion	25,400,000	$ 20,700,000
Finance leases, current portion	$ 13,200,000	$ 9,000,000.0