Loans and Allowance for Credit Losses - Outstanding Balances of Loan (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 7,642,143	$ 6,839,230
Commercial, financial, agricultural and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,211,706	1,173,452
Commercial, financial, agricultural and other [Member] | Time and demand loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,023,824	1,159,524
Commercial, financial, agricultural and other [Member] | Commercial credit cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	13,920	13,928
Commercial, financial, agricultural and other [Member] | Equipment Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	79,674
Commercial, financial, agricultural and other [Member] | Time and Demand Loans Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	94,288
Real Estate Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	513,101	494,456
Real Estate Construction [Member] | Construction Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	395,439
Real Estate Construction [Member] | Construction Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	117,662
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,194,669	1,920,250
Residential Real Estate [Member] | Senior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,547,192	1,299,534
Residential Real Estate [Member] | Junior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	647,477	620,716
Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,425,012	2,251,097
Commercial real estate [Member] | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	431,151	385,432
Commercial real estate [Member] | Nonowner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,510,347	1,465,247
Commercial real estate [Member] | Owner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	483,514	400,418
Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,297,655	999,975
Loans To Individuals [Member] | Automobile Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,210,451	901,280
Loans To Individuals [Member] | Consumer Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	10,657	11,151
Loans To Individuals [Member] | Other consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 76,547	$ 87,544