Off-Balance-Sheet Arrangements, Commitments, Guarantees and Contingencies (Financial Instruments With Off-Balance-Sheet Risk) (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Standby Letters of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments with off- balance-sheet risk	$ 238,690	$ 241,345
Deferred Standby Letter of Credit Fees [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments with off- balance-sheet risk	2,072	1,723
Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments with off- balance-sheet risk	$ 10,420,142	$ 9,814,475