Commitments and Contingent Liabilities - Commitments to Extend Credit, Guarantees and Various Letters of Credit Outstanding (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Lines of credit	$ 4,130,549	$ 3,806,398
Loans approved but not closed	412,089	398,204
Overdraft limits	389,574	380,143
Letters of credit	33,429	30,362
Contingent obligations and other guarantees	$ 30,787	$ 30,782