Loans and ACL - Summary of Recorded Investment of Loans Held for Investment by Internal Loan Grade by Year of Origination Quarterly (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2025	Dec. 31, 2024	Sep. 30, 2024
Financing Receivable, Credit Quality Indicator [Line Items]
2025	$ 18,457	$ 58,252
2024	51,165	181,865
2023	173,949	740,853
2022	717,806	323,241
2021	313,765	260,534
Prior	578,645	340,307
Revolving Loans	205,494	205,703
Total	2,059,281	2,110,755
Current period gross charge-offs	2,789
Current period gross charge-offs 2024	325
Current period gross charge-offs 2023	85
Current period gross charge-offs 2022	2,157
Current period gross charge-offs 2021	6
Current period gross charge-offs prior	166
Current period gross charge-offs revolving	50
Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025	5,226	15,499
2024	11,766	40,237
2023	38,052	107,206
2022	97,039	35,345
2021	34,522	23,150
Prior	36,947	17,987
Revolving Loans	116,547	115,480
Total	340,099	354,904
Current period gross charge-offs	2,123
Current period gross charge-offs 2024	23
Current period gross charge-offs 2023	30
Current period gross charge-offs 2022	1,937
Current period gross charge-offs prior	83
Current period gross charge-offs revolving	50
Construction, Commercial [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025	180	6,219
2024	6,341	7,483
2023	4,895	65,560
2022	64,453	15,367
2021	7,326	10,175
Prior	19,412	9,288
Revolving Loans	399	399
Total	103,006	114,491
Construction, Residential [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025	5,005	19,767
2024	17,829	9,030
2023	7,773	7,992
2022	3,819	13,971
2021	18,278
Prior	55	57
Revolving Loans	739	990
Total	53,498	51,807
Commercial [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025	5,924	6,847
2024	6,755	39,790
2023	40,614	320,210
2022	314,535	137,196
2021	133,906	159,760
Prior	309,074	158,507
Revolving Loans	23,415	25,532
Total	834,223	847,842
Current period gross charge-offs	63
Current period gross charge-offs prior	63
Residential [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025	1,157	3,668
2024	3,108	67,516
2023	66,701	229,615
2022	228,627	118,090
2021	116,841	66,320
Prior	209,946	151,202
Revolving Loans	57,566	55,842
Total	683,946	692,253
Current period gross charge-offs	16
Current period gross charge-offs prior	16
Farmland [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025		147
2024	146	135
2023	132	997
2022	995	1,339
2021	1,322
Prior	2,005	2,753
Revolving Loans	148	149
Total	4,748	5,520
Consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025	965	6,105
2024	5,220	17,674
2023	15,782	9,273
2022	8,338	1,933
2021	1,570	1,129
Prior	1,206	513
Revolving Loans	6,680	7,311
Total	39,761	43,938
Current period gross charge-offs	587
Current period gross charge-offs 2024	302
Current period gross charge-offs 2023	55
Current period gross charge-offs 2022	220
Current period gross charge-offs 2021	6
Current period gross charge-offs prior	4
Risk Grades 1 - 4
Financing Receivable, Credit Quality Indicator [Line Items]
2025	18,230	53,329
2024	46,749	147,386
2023	143,246	618,362
2022	554,044	272,353
2021	248,595	230,603
Prior	499,404	300,706
Revolving Loans	187,227	182,509
Total	1,697,495	1,805,248
Risk Grades 1 - 4 \| Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025	5,226	13,883
2024	10,508	13,559
2023	13,830	64,530
2022	52,822	14,600
2021	12,525	17,405
Prior	28,927	15,760
Revolving Loans	103,283	98,867
Total	227,121	238,604
Risk Grades 1 - 4 \| Construction, Commercial [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025	180	6,219
2024	6,341	6,277
2023	3,694	65,560
2022	46,453	7,776
2021	6,593	5,405
Prior	9,641	4,792
Revolving Loans	399	399
Total	73,301	96,428
Risk Grades 1 - 4 \| Construction, Residential [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025	4,919	19,574
2024	17,829	8,861
2023	7,558	7,837
2022	3,352	13,971
Prior	55	57
Revolving Loans	739	990
Total	34,452	51,290
Risk Grades 1 - 4 \| Commercial [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025	5,924	4,747
2024	4,663	34,698
2023	37,221	245,563
2022	217,275	118,435
2021	114,002	142,211
Prior	259,122	133,856
Revolving Loans	19,007	21,323
Total	657,214	700,833
Risk Grades 1 - 4 \| Residential [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025	1,016	2,815
2024	2,199	66,780
2023	65,597	225,159
2022	225,464	114,682
2021	112,936	64,548
Prior	198,552	143,002
Revolving Loans	56,971	53,498
Total	662,735	670,484
Risk Grades 1 - 4 \| Farmland [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025		147
2024	146
2023		997
2022	995	1,239
2021	1,225
Prior	2,005	2,753
Revolving Loans	148	149
Total	4,519	5,285
Risk Grades 1 - 4 \| Consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025	965	5,944
2024	5,063	17,211
2023	15,346	8,716
2022	7,683	1,650
2021	1,314	1,034
Prior	1,102	486
Revolving Loans	6,680	7,283
Total	38,153	42,324
Risk Grades 5 - 6
Financing Receivable, Credit Quality Indicator [Line Items]
2025	86	2,327
2024	1,939	30,880
2023	28,879	104,708
2022	145,156	26,264
2021	38,661	24,907
Prior	68,296	30,699
Revolving Loans	15,941	19,371
Total	298,958	239,156
Risk Grades 5 - 6 \| Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025		672
2024	397	24,430
2023	23,880	37,503
2022	38,796	10,201
2021	6,939	5,183
Prior	6,209	979
Revolving Loans	11,460	15,092
Total	87,681	94,060
Risk Grades 5 - 6 \| Construction, Commercial [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024		1,090
2023	1,086
2022	18,000	7,567
2021	714	4,770
Prior	9,584	4,235
Total	29,384	17,662
Risk Grades 5 - 6 \| Construction, Residential [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025	86	193
2023	215
2021	18,278
Total	18,579	193
Risk Grades 5 - 6 \| Commercial [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025		535
2024	532	5,092
2023	3,393	64,677
2022	87,068	7,002
2021	10,375	14,604
Prior	47,782	23,104
Revolving Loans	4,383	4,184
Total	153,533	119,198
Risk Grades 5 - 6 \| Residential [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025		853
2024	909
2023		2,303
2022	998	1,295
2021	2,182	318
Prior	4,692	2,378
Revolving Loans	98	95
Total	8,879	7,242
Risk Grades 5 - 6 \| Farmland [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024		135
2023	132
2022		100
2021	97
Total	229	235
Risk Grades 5 - 6 \| Consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025		74
2024	101	133
2023	173	225
2022	294	99
2021	76	32
Prior	29	3
Total	673	566
Risk Grade 7
Financing Receivable, Credit Quality Indicator [Line Items]
2025	141	2,596
2024	2,477	3,599
2023	1,817	17,783
2022	18,606	23,163
2021	23,165	5,024
Prior	10,945	8,709
Revolving Loans	2,326	3,823
Total	59,477	64,697
Risk Grade 7 \| Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025		944
2024	861	2,248
2023	342	5,173
2022	5,421	10,462
2021	13,053	562
Prior	1,811	1,247
Revolving Loans	1,804	1,521
Total	23,292	22,157
Risk Grade 7 \| Construction, Commercial [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024		116
2023	115
2022		24
2021	19
Prior	187	261
Total	321	401
Risk Grade 7 \| Construction, Residential [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024		169
2023		155
2022	467
Total	467	324
Risk Grade 7 \| Commercial [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025		1,565
2024	1,560
2023		9,970
2022	10,192	10,380
2021	8,190	2,945
Prior	2,170	1,355
Revolving Loans	25	25
Total	22,137	26,240
Risk Grade 7 \| Residential [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025	141
2024		736
2023	1,104	2,153
2022	2,165	2,113
2021	1,723	1,454
Prior	6,702	5,822
Revolving Loans	497	2,249
Total	12,332	14,527
Risk Grade 7 \| Consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2025		87
2024	56	330
2023	256	332	$ 7
2022	361	184
2021	180	63
Prior	75	24
Revolving Loans		28
Total	928	1,048
Risk Grade 8
Financing Receivable, Credit Quality Indicator [Line Items]
2023	7
2022		1,461
2021	3,344
Prior		193
Total	3,351	1,654
Risk Grade 8 \| Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022		82
2021	2,005
Prior		1
Total	2,005	83
Risk Grade 8 \| Commercial [Member] \| Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022		1,379
2021	1,339
Prior		192
Total	1,339	$ 1,571
Risk Grade 8 \| Consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 7

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