Loans And Allowance For Credit Losses - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounts Notes And Loans Receivable [Line Items]
Loans held by subsidiaries subject to blanket liens	$ 4,980,020,000
Line of credit	0	$ 0
Nonaccrual, past due 90 days or more and still accruing, restructured loans and foreclosed assets	35,096,000	24,325,000
Nonaccrual loans	33,609,000	24,325,000
Interest income recognized on impaired loans	1,714,000	1,607,000	$ 2,122,000
Additional funds advanced in connection with impaired loans	0
Unfunded loan commitments	7,903,000	12,323,000
Provision for loan losses	15,050,000	11,540,000
Total Loans	7,148,791,000	6,441,868,000
Reserve for unfunded commitments (Other liabilities)	7,903,000	12,323,000
Reversal of Provision for credit losses		11,540,000
Available line of credit	1,858,173,000
Undisbursed Commitments	813,000,000
Unfunded Loan Commitment [Member]
Accounts Notes And Loans Receivable [Line Items]
Unfunded loan commitments	$ 4,419,000	$ 5,887,000