Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Standby letters of credit and surety bonds	$ 32.5
Outstanding commitments to fund new loan and lease transactions	$ 1,363.3
Funding commitments for loans and leases expiration period	90 days
Other commitments due in 2023	$ 83.2
Other commitments due in 2024	17.4
Other commitments due in 2025	4.9
Other commitments due in 2026	2.2
Other commitments due in 2027	0.1
Other commitments due in 2027 and beyond	0.5
Environmental activities expenditures	$ 4.6	$ 4.0	$ 1.9
Environmental Remediation Expense, Statement of Income or Comprehensive Income [Extensible Enumeration]	Costs And Expenses	Costs And Expenses	Costs And Expenses