Loans and ACL - Summary of Aging of amortized cost of loans held for investment by loan category (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Financing Receivable, Past Due [Line Items]
Days past due	$ 2,457,325
Nonaccrual	28,557	$ 10,324
Total Past Due & Nonaccrual		35,552
Gross loans	2,457,325	2,412,699
Less: deferred loan fees, net of costs	(345)	(1,640)
Total	2,456,980	2,411,059
Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	28,557
Nonaccrual loans with no allowance | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	10,888
Non accrual loans with an allowance | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	17,669
30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total	8,986	14,663
60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total	2,051	2,305
Greater than 90 Days Past Due & Accruing [Member]
Financing Receivable, Past Due [Line Items]
Total	2,167	8,260
PCI Loans [Member]
Financing Receivable, Past Due [Line Items]
PCI Loans		58,748
Current Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable Recorded Investments Current	2,415,219	2,316,759
Less: deferred loan fees, net of costs	(345)	(1,640)
Commercial and Industrial [Member]
Financing Receivable, Past Due [Line Items]
Days past due	571,095
Nonaccrual	8,651	2,314
Total Past Due & Nonaccrual		3,081
Gross loans	571,095	590,049
Commercial and Industrial [Member] | Nonaccrual loans with no allowance
Financing Receivable, Past Due [Line Items]
Nonaccrual	186
Commercial and Industrial [Member] | Non accrual loans with an allowance
Financing Receivable, Past Due [Line Items]
Nonaccrual	8,465
Commercial and Industrial [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days past due	1,122	488
Commercial and Industrial [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days past due	61	279
Commercial and Industrial [Member] | PCI Loans [Member]
Financing Receivable, Past Due [Line Items]
PCI Loans		1,481
Commercial and Industrial [Member] | Current Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable Recorded Investments Current	561,261	585,487
Paycheck Protection Program [Member]
Financing Receivable, Past Due [Line Items]
Days past due	7,988
Gross loans	7,988	11,967
Paycheck Protection Program [Member] | Current Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable Recorded Investments Current	7,988	11,967
Construction, commercial [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	437
Construction, commercial [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	180,149
Nonaccrual	437	714
Total Past Due & Nonaccrual		1,869
Gross loans	180,149	183,301
Construction, commercial [Member] | Nonaccrual loans with no allowance
Financing Receivable, Past Due [Line Items]
Nonaccrual	0
Construction, commercial [Member] | Non accrual loans with an allowance
Financing Receivable, Past Due [Line Items]
Nonaccrual	437
Construction, commercial [Member] | 30-59 Days Past Due [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	1,106	1,136
Construction, commercial [Member] | 60-89 Days Past Due [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	867	19
Construction, commercial [Member] | Current Loans [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable Recorded Investments Current	177,739	181,432
Construction, Residential [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	92,403
Total Past Due & Nonaccrual		2,620
Gross loans	92,403	76,599
Construction, Residential [Member] | 30-59 Days Past Due [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	399	1,416
Construction, Residential [Member] | 60-89 Days Past Due [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	388	1,204
Construction, Residential [Member] | PCI Loans [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
PCI Loans		7
Construction, Residential [Member] | Current Loans [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable Recorded Investments Current	91,616	73,972
Mortgage, Commercial [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	867,916
Nonaccrual	11,571	1,658
Total Past Due & Nonaccrual		14,388
Gross loans	867,916	864,989
Mortgage, Commercial [Member] | Nonaccrual loans with no allowance | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	10,108
Mortgage, Commercial [Member] | Non accrual loans with an allowance | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	1,463
Mortgage, Commercial [Member] | 30-59 Days Past Due [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	960	6,199
Mortgage, Commercial [Member] | 60-89 Days Past Due [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due		297
Mortgage, Commercial [Member] | Greater than 90 Days Past Due & Accruing [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due		6,234
Mortgage, Commercial [Member] | PCI Loans [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
PCI Loans		51,223
Mortgage, Commercial [Member] | Current Loans [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable Recorded Investments Current	855,385	799,378
Mortgage, Residential [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	672,473
Nonaccrual	7,447	5,143
Total Past Due & Nonaccrual		11,916
Gross loans	672,473	631,772
Mortgage, Residential [Member] | Nonaccrual loans with no allowance | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	592
Mortgage, Residential [Member] | Non accrual loans with an allowance | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	6,855
Mortgage, Residential [Member] | 30-59 Days Past Due [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	4,153	4,544
Mortgage, Residential [Member] | 60-89 Days Past Due [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	585	231
Mortgage, Residential [Member] | Greater than 90 Days Past Due & Accruing [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	1,998	1,998
Mortgage, Residential [Member] | PCI Loans [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
PCI Loans		5,678
Mortgage, Residential [Member] | Current Loans [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable Recorded Investments Current	658,290	614,178
Mortgage, Farmland [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due	6,394
Total Past Due & Nonaccrual		75
Gross loans	6,394	6,599
Mortgage, Farmland [Member] | 60-89 Days Past Due [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Days past due		75
Mortgage, Farmland [Member] | Current Loans [Member] | Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable Recorded Investments Current	6,394	6,524
Consumer [Member]
Financing Receivable, Past Due [Line Items]
Days past due	58,907
Nonaccrual	451	495
Total Past Due & Nonaccrual		1,603
Gross loans	58,907	47,423
Consumer [Member] | Nonaccrual loans with no allowance
Financing Receivable, Past Due [Line Items]
Nonaccrual	2
Consumer [Member] | Non accrual loans with an allowance
Financing Receivable, Past Due [Line Items]
Nonaccrual	449
Consumer [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days past due	1,246	880
Consumer [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Days past due	150	200
Consumer [Member] | Greater than 90 Days Past Due & Accruing [Member]
Financing Receivable, Past Due [Line Items]
Days past due	169	28
Consumer [Member] | PCI Loans [Member]
Financing Receivable, Past Due [Line Items]
PCI Loans		359
Consumer [Member] | Current Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable Recorded Investments Current	$ 56,891	$ 45,461