Loans and ACL - Summary of Amortized Cost of Loans Held for Investment by Internal Loan Grade by Year of Orgination (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
2023	$ 200,569		$ 200,569
2022	824,797		824,797
2021	376,282		376,282
2020	311,874		311,874
2019	110,805		110,805
Prior	376,640		376,640
Revolving Loans	257,637		257,637
Total	2,458,604		2,458,604
Current period gross charge-offs	9,020	$ 2,791	10,329	$ 5,567
Current period gross charge-offs 2023			571
Current period gross charge-offs 2022			1,098
Current period gross charge-offs 2021			170
Current period gross charge-offs 2020			521
Current period gross charge-offs 2019			666
Current period gross charge-offs prior			78
Current period gross charge-offs revolving			7,225
Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	65,028		65,028
2022	194,112		194,112
2021	57,103		57,103
2020	41,936		41,936
2019	14,134		14,134
Prior	18,956		18,956
Revolving Loans	154,652		154,652
Total	545,921		545,921
Current period gross charge-offs	7,326	1,383	8,095	3,746
Current period gross charge-offs 2022			198
Current period gross charge-offs 2021			39
Current period gross charge-offs 2019			625
Current period gross charge-offs prior			9
Current period gross charge-offs revolving			7,224
Paycheck Protection Program [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	7,234		7,234
Total	7,234		7,234
Construction, commercial [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	4,684		4,684
2022		62,760		62,760
2021	52,790		52,790
2020	16,725		16,725
2019	2,345		2,345
Prior	9,947		9,947
Revolving Loans	16,612		16,612
Total	165,863		165,863
Current period gross charge-offs			28
Construction, Residential [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	27,236		27,236
2022	42,009		42,009
2021	8,471		8,471
2020	932		932
2019	1,194		1,194
Prior	71		71
Revolving Loans	2,286		2,286
Total	82,199		82,199
Mortgage, Commercial [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	29,516		29,516
2022	294,156		294,156
2021	124,779		124,779
2020	172,947		172,947
2019	57,515		57,515
Prior	184,987		184,987
Revolving Loans	15,829		15,829
Total	879,729		879,729
Mortgage, Residential [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	50,393		50,393
2022	213,748		213,748
2021	119,566		119,566
2020	75,270		75,270
2019	32,125		32,125
Prior	159,535		159,535
Revolving Loans	58,928		58,928
Total	709,565		709,565
Current period gross charge-offs			1,256
Current period gross charge-offs 2023			0
Current period gross charge-offs 2022			744
Current period gross charge-offs 2020			498
Current period gross charge-offs prior			14
Mortgage, Farmland [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	729		729
2021	1,424		1,424
2019	1,549		1,549
Prior	1,624		1,624
Revolving Loans	257		257
Total	5,583		5,583
Consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	23,712		23,712
2022	17,283		17,283
2021	4,915		4,915
2020	4,064		4,064
2019	1,943		1,943
Prior	1,520		1,520
Revolving Loans	9,073		9,073
Total	62,510		62,510
Current period gross charge-offs	1,694	$ 329	950	$ 605
Current period gross charge-offs 2023			571
Current period gross charge-offs 2022			156
Current period gross charge-offs 2021			131
Current period gross charge-offs 2020			23
Current period gross charge-offs 2019			41
Current period gross charge-offs prior			27
Current period gross charge-offs revolving			1
Risk Grades 1 - 4
Financing Receivable, Credit Quality Indicator [Line Items]
2023	172,079		172,079
2022	717,625		717,625
2021	343,874		343,874
2020	277,933		277,933
2019	92,868		92,868
Prior	319,591		319,591
Revolving Loans	226,555		226,555
Total	2,150,525		2,150,525
Risk Grades 1 - 4 | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	36,665		36,665
2022	131,441		131,441
2021	44,931		44,931
2020	31,890		31,890
2019	12,814		12,814
Prior	17,085		17,085
Revolving Loans	135,331		135,331
Total	410,157		410,157
Risk Grades 1 - 4 | Paycheck Protection Program [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	7,234		7,234
Total	7,234		7,234
Risk Grades 1 - 4 | Construction, commercial [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	4,684		4,684
2022	56,296		56,296
2021	46,538		46,538
2020	16,193		16,193
2019	2,345		2,345
Prior	8,865		8,865
Revolving Loans	10,820		10,820
Total	145,741		145,741
Risk Grades 1 - 4 | Construction, Residential [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	27,215		27,215
2022	39,151		39,151
2021	7,998		7,998
2020	347		347
2019	1,194		1,194
Prior	71		71
Revolving Loans	2,046		2,046
Total	78,022		78,022
Risk Grades 1 - 4 | Mortgage, Commercial [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	29,516		29,516
2022	268,410		268,410
2021	113,715		113,715
2020	153,897		153,897
2019	44,080		44,080
Prior	144,333		144,333
Revolving Loans	11,689		11,689
Total	765,640		765,640
Risk Grades 1 - 4 | Mortgage, Residential [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	50,358		50,358
2022	204,528		204,528
2021	117,255		117,255
2020	71,731		71,731
2019	29,032		29,032
Prior	146,643		146,643
Revolving Loans	57,415		57,415
Total	676,962		676,962
Risk Grades 1 - 4 | Mortgage, Farmland [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	729		729
2021	1,424		1,424
2019	1,549		1,549
Prior	1,624		1,624
Revolving Loans	211		211
Total	5,537		5,537
Risk Grades 1 - 4 | Consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	23,641		23,641
2022	17,070		17,070
2021	4,779		4,779
2020	3,875		3,875
2019	1,854		1,854
Prior	970		970
Revolving Loans	9,043		9,043
Total	61,232		61,232
Risk Grades 5 - 6
Financing Receivable, Credit Quality Indicator [Line Items]
2023	28,454		28,454
2022	45,016		45,016
2021	21,481		21,481
2020	26,456		26,456
2019	16,240		16,240
Prior	41,409		41,409
Revolving Loans	28,714		28,714
Total	207,770		207,770
Risk Grades 5 - 6 | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	6,252		6,252
Risk Grades 5 - 6 | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	28,363		28,363
2022	1,904		1,904
2021	9,964		9,964
2020	6,793		6,793
2019	450		450
Prior	1,827		1,827
Revolving Loans	17,375		17,375
Total	66,676		66,676
Risk Grades 5 - 6 | Construction, commercial [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	6,464		6,464
2020	532		532
Prior	840		840
Revolving Loans	5,792		5,792
Total	19,880		19,880
Risk Grades 5 - 6 | Construction, Residential [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	2,278		2,278
2021	473		473
2020	585		585
Revolving Loans	240		240
Total	3,576		3,576
Risk Grades 5 - 6 | Mortgage, Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	96,542		96,542
Risk Grades 5 - 6 | Mortgage, Commercial [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	25,746		25,746
2021	4,757		4,757
2020	16,870		16,870
2019	13,304		13,304
Prior	31,823		31,823
Revolving Loans	4,042		4,042
Total					$ 17,547
Risk Grades 5 - 6 | Mortgage, Residential [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	35		35
2022	8,570		8,570
2021	24		24
2020	1,605		1,605
2019	2,482		2,482
Prior	6,475		6,475
Revolving Loans	1,189		1,189
Total	20,380		20,380
Risk Grades 5 - 6 | Mortgage, Farmland [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans	46		46
Total	46		46
Risk Grades 5 - 6 | Consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	56		56
2022	54		54
2021	11		11
2020	71		71
2019	4		4
Prior	444		444
Revolving Loans	30		30
Total	670		670
Risk Grade 7
Financing Receivable, Credit Quality Indicator [Line Items]
2023	36		36
2022	56,818		56,818
2021	10,891		10,891
2020	7,485		7,485
2019	1,697		1,697
Prior	15,640		15,640
Revolving Loans	1,989		1,989
Total	94,556		94,556
Risk Grade 7 | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0		0
2022	55,429		55,429
2021	2,172		2,172
2020	3,253		3,253
2019	870		870
Prior	44		44
Revolving Loans	1,567		1,567
Total	63,335		63,335
Risk Grade 7 | Construction, commercial [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Prior	242		242
Total	242		242
Risk Grade 7 | Construction, Residential [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	21		21
2022	580		580
Total	601		601
Risk Grade 7 | Mortgage, Commercial [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	6,307		6,307
2020	2,180		2,180
2019	131		131
Prior	8,831		8,831
Risk Grade 7 | Mortgage, Residential [Member] | Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	650		650
2021	2,287		2,287
2020	1,934		1,934
2019	611		611
Prior	6,417		6,417
Revolving Loans	324		324
Total	12,223		12,223
Risk Grade 7 | Consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	15		15
2022	159		159
2021	125		125
2020	118		118
2019	85		85
Prior	106		106
Total	608		608
Risk Grade 8
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0		0
2022	5,338		5,338
2021	36		36
2020	0		0
2019	0		0
Prior	0		0
Revolving Loans	379		379
Total	$ 5,753		$ 5,753