Loans and Leases - Age Analysis of Past Due Loans and Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing loans and leases	$ 6,109,877	$ 5,276,807
Nonaccrual loans and leases	13,353	33,210
Total loans and leases held for investment	6,123,230	5,310,017
Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	14,254	9,036
Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	1,717	1,609
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	875	498
Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	16,846	11,143
Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	6,093,031	5,265,664
Commercial, Financial and Agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing loans and leases	1,081,709	955,948
Nonaccrual loans and leases	5,072	448
Total loans and leases held for investment	1,086,781	956,396
Commercial, Financial and Agricultural [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	1,616	3,407
Commercial, Financial and Agricultural [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	343	894
Commercial, Financial and Agricultural [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	0	0
Commercial, Financial and Agricultural [Member] | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	1,959	4,301
Commercial, Financial and Agricultural [Member] | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	1,079,750	951,647
Paycheck Protection Program Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing loans and leases	2,147	31,748
Nonaccrual loans and leases	0	0
Total loans and leases held for investment	2,147	31,748
Paycheck Protection Program Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	0	367
Paycheck Protection Program Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	0	0
Paycheck Protection Program Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	0	0
Paycheck Protection Program Loans [Member] | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	0	367
Paycheck Protection Program Loans [Member] | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	2,147	31,381
Real Estate-Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing loans and leases	3,023,418	2,690,635
Nonaccrual loans and leases	4,537	27,900
Total loans and leases held for investment	3,027,955	2,718,535
Real Estate-Commercial [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	3,281	234
Real Estate-Commercial [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	290	0
Real Estate-Commercial [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	20	0
Real Estate-Commercial [Member] | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	3,591	234
Real Estate-Commercial [Member] | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	3,019,827	2,690,401
Real Estate-Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing loans and leases	381,811	283,918
Nonaccrual loans and leases	0	0
Total loans and leases held for investment	381,811	283,918
Real Estate-Construction [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	315	0
Real Estate-Construction [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	0	0
Real Estate-Construction [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	0	0
Real Estate-Construction [Member] | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	315	0
Real Estate-Construction [Member] | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	381,496	283,918
Real Estate-Residential Secured for Business Purpose [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing loans and leases	477,241	407,713
Nonaccrual loans and leases	1,013	2,187
Total loans and leases held for investment	478,254	409,900
Real Estate-Residential Secured for Business Purpose [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	375	542
Real Estate-Residential Secured for Business Purpose [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	203	0
Real Estate-Residential Secured for Business Purpose [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	263	216
Real Estate-Residential Secured for Business Purpose [Member] | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	841	758
Real Estate-Residential Secured for Business Purpose [Member] | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	476,400	406,955
Real Estate-Residential Secured for Personal Purpose [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing loans and leases	728,406	538,517
Nonaccrual loans and leases	1,989	2,049
Total loans and leases held for investment	730,395	540,566
Real Estate-Residential Secured for Personal Purpose [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	4,127	2,976
Real Estate-Residential Secured for Personal Purpose [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	162	162
Real Estate-Residential Secured for Personal Purpose [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	319	0
Real Estate-Residential Secured for Personal Purpose [Member] | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	4,608	3,138
Real Estate-Residential Secured for Personal Purpose [Member] | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	723,798	535,379
Real Estate-Home Equity Secured for Personal Purpose [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing loans and leases	175,959	158,364
Nonaccrual loans and leases	740	545
Total loans and leases held for investment	176,699	158,909
Real Estate-Home Equity Secured for Personal Purpose [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	953	646
Real Estate-Home Equity Secured for Personal Purpose [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	225	129
Real Estate-Home Equity Secured for Personal Purpose [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	0	0
Real Estate-Home Equity Secured for Personal Purpose [Member] | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	1,178	775
Real Estate-Home Equity Secured for Personal Purpose [Member] | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	174,781	157,589
Loans to Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing loans and leases	27,873	25,504
Nonaccrual loans and leases	0	0
Total loans and leases held for investment	27,873	25,504
Loans to Individuals [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	32	90
Loans to Individuals [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	153	27
Loans to Individuals [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	39	180
Loans to Individuals [Member] | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	224	297
Loans to Individuals [Member] | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	27,649	25,207
Lease Financings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing loans and leases	211,313	184,460
Nonaccrual loans and leases	2	81
Total loans and leases held for investment	211,315	184,541
Lease Financings [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	3,555	774
Lease Financings [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	341	397
Lease Financings [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	234	102
Lease Financings [Member] | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	4,130	1,273
Lease Financings [Member] | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivables, gross	$ 207,183	$ 183,187