Allowance for Credit Losses - Analysis of Past Due and Nonaccrual Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Financing Receivable, Past Due [Line Items]
Financing receivable	$ 6,520,740	$ 6,450,447
Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	4,343,924	4,359,083
Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	1,252,225	1,240,743
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Financing receivable	576,247	569,921
Construction
Financing Receivable, Past Due [Line Items]
Financing receivable	278,425	211,560
Agriculture production
Financing Receivable, Past Due [Line Items]
Financing receivable	61,337	61,414
Leases
Financing Receivable, Past Due [Line Items]
Financing receivable	8,582	7,726
CRE non-owner occupied | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	2,143,146	2,149,725
CRE owner occupied | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	972,361	984,807
Multifamily | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	951,590	944,537
Farmland | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	276,827	280,014
SFR 1-4 1st DT liens | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	829,346	790,349
SFR HELOCs and junior liens | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	363,600	393,666
Other | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	59,279	56,728
Financial Asset Originated
Financing Receivable, Past Due [Line Items]
Financing receivable	6,520,740	6,450,447
Financial Asset Originated | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	4,343,924	4,359,083
Financial Asset Originated | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	1,252,225	1,240,743
Financial Asset Originated | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Financing receivable	576,247	569,921
Financial Asset Originated | Construction
Financing Receivable, Past Due [Line Items]
Financing receivable	278,425	211,560
Financial Asset Originated | Agriculture production
Financing Receivable, Past Due [Line Items]
Financing receivable	61,337	61,414
Financial Asset Originated | Leases
Financing Receivable, Past Due [Line Items]
Financing receivable	8,582	7,726
Financial Asset Originated | CRE non-owner occupied | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	2,143,146	2,149,725
Financial Asset Originated | CRE owner occupied | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	972,361	984,807
Financial Asset Originated | Multifamily | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	951,590	944,537
Financial Asset Originated | Farmland | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	276,827	280,014
Financial Asset Originated | SFR 1-4 1st DT liens | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	829,346	790,349
Financial Asset Originated | SFR HELOCs and junior liens | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	363,600	393,666
Financial Asset Originated | Other | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	59,279	56,728
Total Past Due Loans | Financial Asset Originated
Financing Receivable, Past Due [Line Items]
Financing receivable	9,483	4,947
Total Past Due Loans | Financial Asset Originated | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	2,750	332
Total Past Due Loans | Financial Asset Originated | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	4,583	1,463
Total Past Due Loans | Financial Asset Originated | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Financing receivable	1,717	2,773
Total Past Due Loans | Financial Asset Originated | Construction
Financing Receivable, Past Due [Line Items]
Financing receivable	400	379
Total Past Due Loans | Financial Asset Originated | Agriculture production
Financing Receivable, Past Due [Line Items]
Financing receivable	33	0
Total Past Due Loans | Financial Asset Originated | Leases
Financing Receivable, Past Due [Line Items]
Financing receivable	0	0
Total Past Due Loans | Financial Asset Originated | CRE non-owner occupied | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	651	0
Total Past Due Loans | Financial Asset Originated | CRE owner occupied | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	441	173
Total Past Due Loans | Financial Asset Originated | Multifamily | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	0	159
Total Past Due Loans | Financial Asset Originated | Farmland | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	1,658	0
Total Past Due Loans | Financial Asset Originated | SFR 1-4 1st DT liens | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	1,591	303
Total Past Due Loans | Financial Asset Originated | SFR HELOCs and junior liens | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	2,636	1,045
Total Past Due Loans | Financial Asset Originated | Other | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	356	115
30-59 days | Financial Asset Originated
Financing Receivable, Past Due [Line Items]
Financing receivable	3,303	2,681
30-59 days | Financial Asset Originated | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	645	159
30-59 days | Financial Asset Originated | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	2,100	222
30-59 days | Financial Asset Originated | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Financing receivable	158	2,300
30-59 days | Financial Asset Originated | Construction
Financing Receivable, Past Due [Line Items]
Financing receivable	400	0
30-59 days | Financial Asset Originated | Agriculture production
Financing Receivable, Past Due [Line Items]
Financing receivable	0	0
30-59 days | Financial Asset Originated | Leases
Financing Receivable, Past Due [Line Items]
Financing receivable	0	0
30-59 days | Financial Asset Originated | CRE non-owner occupied | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	304	0
30-59 days | Financial Asset Originated | CRE owner occupied | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	191	0
30-59 days | Financial Asset Originated | Multifamily | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	0	159
30-59 days | Financial Asset Originated | Farmland | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	150	0
30-59 days | Financial Asset Originated | SFR 1-4 1st DT liens | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	1	24
30-59 days | Financial Asset Originated | SFR HELOCs and junior liens | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	1,918	172
30-59 days | Financial Asset Originated | Other | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	181	26
60-89 days | Financial Asset Originated
Financing Receivable, Past Due [Line Items]
Financing receivable	733	488
60-89 days | Financial Asset Originated | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	0	98
60-89 days | Financial Asset Originated | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	573	200
60-89 days | Financial Asset Originated | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Financing receivable	160	190
60-89 days | Financial Asset Originated | Construction
Financing Receivable, Past Due [Line Items]
Financing receivable	0	0
60-89 days | Financial Asset Originated | Agriculture production
Financing Receivable, Past Due [Line Items]
Financing receivable	0	0
60-89 days | Financial Asset Originated | Leases
Financing Receivable, Past Due [Line Items]
Financing receivable	0	0
60-89 days | Financial Asset Originated | CRE non-owner occupied | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	0	0
60-89 days | Financial Asset Originated | CRE owner occupied | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	0	98
60-89 days | Financial Asset Originated | Multifamily | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	0	0
60-89 days | Financial Asset Originated | Farmland | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	0	0
60-89 days | Financial Asset Originated | SFR 1-4 1st DT liens | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	106	0
60-89 days | Financial Asset Originated | SFR HELOCs and junior liens | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	391	166
60-89 days | Financial Asset Originated | Other | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	76	34
> 90 days | Financial Asset Originated
Financing Receivable, Past Due [Line Items]
Financing receivable	5,447	1,778
> 90 days | Financial Asset Originated | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	2,105	75
> 90 days | Financial Asset Originated | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	1,910	1,041
> 90 days | Financial Asset Originated | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Financing receivable	1,399	283
> 90 days | Financial Asset Originated | Construction
Financing Receivable, Past Due [Line Items]
Financing receivable	0	379
> 90 days | Financial Asset Originated | Agriculture production
Financing Receivable, Past Due [Line Items]
Financing receivable	33	0
> 90 days | Financial Asset Originated | Leases
Financing Receivable, Past Due [Line Items]
Financing receivable	0	0
> 90 days | Financial Asset Originated | CRE non-owner occupied | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	347	0
> 90 days | Financial Asset Originated | CRE owner occupied | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	250	75
> 90 days | Financial Asset Originated | Multifamily | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	0	0
> 90 days | Financial Asset Originated | Farmland | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	1,508	0
> 90 days | Financial Asset Originated | SFR 1-4 1st DT liens | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	1,484	279
> 90 days | Financial Asset Originated | SFR HELOCs and junior liens | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	327	707
> 90 days | Financial Asset Originated | Other | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	99	55
Current | Financial Asset Originated
Financing Receivable, Past Due [Line Items]
Financing receivable	6,511,257	6,445,500
Current | Financial Asset Originated | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	4,341,174	4,358,751
Current | Financial Asset Originated | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	1,247,642	1,239,280
Current | Financial Asset Originated | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Financing receivable	574,530	567,148
Current | Financial Asset Originated | Construction
Financing Receivable, Past Due [Line Items]
Financing receivable	278,025	211,181
Current | Financial Asset Originated | Agriculture production
Financing Receivable, Past Due [Line Items]
Financing receivable	61,304	61,414
Current | Financial Asset Originated | Leases
Financing Receivable, Past Due [Line Items]
Financing receivable	8,582	7,726
Current | Financial Asset Originated | CRE non-owner occupied | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	2,142,495	2,149,725
Current | Financial Asset Originated | CRE owner occupied | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	971,920	984,634
Current | Financial Asset Originated | Multifamily | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	951,590	944,378
Current | Financial Asset Originated | Farmland | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable	275,169	280,014
Current | Financial Asset Originated | SFR 1-4 1st DT liens | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	827,755	790,046
Current | Financial Asset Originated | SFR HELOCs and junior liens | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	360,964	392,621
Current | Financial Asset Originated | Other | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable	$ 58,923	$ 56,613