Loans and Allowance for Credit Losses - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) Contract	Dec. 31, 2020 USD ($) Contract	Dec. 31, 2019 USD ($) Contract
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non Accrual Status Of Loans After Number Of Days Past Due	90 days
Loans Receivable Held-for-sale, Amount	$ 18,583	$ 33,436
Provision for credit losses	(377)	53,472
Charge-offs	13,058	19,250
Recorded Investment	$ 55,180	$ 54,053
Number of loans modified | Contract	30	41	38
Total amount of loan modified	$ 1,690	$ 13,969	$ 1,928
Total gains or losses included in earnings		0
Loans with modification to rate and payment due to amortization	$ 400	800	800
Minimum days required for conversion of trouble debt to be in default	90 days
Unearned Deferred (Fees) Costs on Loans	$ (800)	(6,000)
Unearned Premiums	(6,000)	(7,000)
Loans	6,839,230	6,761,183	6,189,148
Loans and Leases Receivable, Gross	$ 6,839,230	6,761,183
Forecasted Value, National Unemployment, Percent	4.34%
Weighted Average [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Forecasted Value, National Unemployment, Percent	4.75%
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Forecasted Value, National Unemployment, Percent	4.91%
Total Deferrals Still in Forbearance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross	$ 6,200
Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unfunded commitments related to nonperforming loans	$ 200	200
Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non Accrual Status Of Loans After Number Of Days Past Due	150 days
Nonaccrual Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable Held-for-sale, Amount	$ 0	13
Gain (loss) on sale of impaired loans	400	0	$ 400
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] | Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Off balance sheet reserve to nonperforming loans	0	26
Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,173,452	1,555,986
Loans and Leases Receivable, Gross	1,173,452	1,555,986
Commercial Loan [Member] | Payroll Protection Program Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 71,300	$ 478,900