Loans Held-for-Investment and Allowance for Credit Losses - Schedule of Company's gross charge-offs by origination year and loan class (Detail) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025	Mar. 31, 2025
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	$ 868,379
2025	2,755,342	$ 3,092,148
2024	1,256,967	1,422,150
2023	726,755	800,553
2022	1,159,212	1,227,189
2021		672,313
Prior	1,270,533	700,700
Revolving Loans Amortized Cost Basis	247,932	243,223
Total	8,285,120	8,158,276
Total Charge-Offs
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	0
2025	157		$ 0
2024	323		125
2023	338		204
2022	94		541
2021			45
Prior	262		31
Revolving Loans Amortized Cost Basis	0		0
Total	1,174		946
C&I [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	185,870
2025	551,304	650,545
2024	168,631	193,758
2023	90,950	105,170
2022	89,346	96,979
2021		33,479
Prior	63,830	36,530
Revolving Loans Amortized Cost Basis	0	0
Total	1,149,931	1,116,461
C&I [Member] \| Total Charge-Offs
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	0
2025	28		0
2024	125		0
2023	6		52
2022	9		20
2021			0
Prior	70		19
Revolving Loans Amortized Cost Basis	0		0
Total	238		91
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	66,737
2025	129,898	143,286
2024	29,342	31,910
2023	22,544	22,971
2022	65,198	70,735
2021		9,760
Prior	70,754	63,839
Revolving Loans Amortized Cost Basis	0	0
Total	384,473	342,501
Construction & Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	180,517
2025	680,258	774,591
2024	126,425	183,137
2023	78,578	86,985
2022	49,992	55,051
2021		45,210
Prior	51,591	11,568
Revolving Loans Amortized Cost Basis	1,676	1,323
Total	1,169,037	1,157,865
Construction & Development [Member] \| Total Charge-Offs
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	0
2025	0
2024	0
2023	0
2022	0
Prior	22
Revolving Loans Amortized Cost Basis	0
Total	22
Farm [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	29,408
2025	86,591	92,299
2024	50,777	57,910
2023	27,898	31,917
2022	58,592	59,931
2021		53,598
Prior	75,885	31,970
Revolving Loans Amortized Cost Basis	0	0
Total	329,151	327,625
Non-Owner Occupied CRE [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	45,960
2025	174,769	183,328
2024	122,243	133,373
2023	48,080	60,214
2022	232,307	239,064
2021		124,904
Prior	202,412	91,933
Revolving Loans Amortized Cost Basis	0	0
Total	825,771	832,816
Owner Occupied CRE [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	78,282
2025	225,768	226,943
2024	160,627	175,382
2023	92,876	98,966
2022	255,152	269,976
2021		163,204
Prior	319,409	186,137
Revolving Loans Amortized Cost Basis	0	0
Total	1,132,114	1,120,608
Owner Occupied CRE [Member] \| Total Charge-Offs
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	0
2025	0		0
2024	0		0
2023	0		0
2022	0		175
2021			0
Prior	150		0
Revolving Loans Amortized Cost Basis	0		0
Total	150		175
Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	132,635
2025	465,015	495,485
2024	382,123	397,363
2023	293,126	307,915
2022	340,690	353,090
2021		221,521
Prior	469,137	275,458
Revolving Loans Amortized Cost Basis	239,371	234,998
Total	2,322,097	2,285,830
Residential [Member] \| Total Charge-Offs
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	0
2025	0		0
2024	42		0
2023	95		102
2022	0		148
2021			0
Prior	3		0
Revolving Loans Amortized Cost Basis	0		0
Total	140		250
Auto [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	110,120
2025	334,941	371,965
2024	185,859	212,681
2023	55,870	66,866
2022	52,503	64,208
2021		14,533
Prior	11,990	2,098
Revolving Loans Amortized Cost Basis	0	0
Total	751,283	732,351
Auto [Member] \| Total Charge-Offs
Financing Receivable, Allowance for Credit Losses [Line Items]
2025	43		0
2024	76		110
2023	146		32
2022	76		178
2021			19
Prior	17		0
Revolving Loans Amortized Cost Basis	0		0
Total	358		339
Non-Auto [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	21,024
2025	56,407	70,059
2024	26,256	30,547
2023	14,298	16,557
2022	13,798	15,802
2021		5,508
Prior	5,012	1,068
Revolving Loans Amortized Cost Basis	6,885	6,902
Total	143,680	146,443
Non-Auto [Member] \| Total Charge-Offs
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	0
2025	86		0
2024	40		15
2023	91		18
2022	9		20
2021			26
Prior	0		12
Revolving Loans Amortized Cost Basis	0		0
Total	226		$ 91
Agriculture [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	17,826
2025	50,391	83,647
2024	4,684	6,089
2023	2,535	2,992
2022	1,634	2,353
2021		596
Prior	513	99
Revolving Loans Amortized Cost Basis	0	0
Total	77,583	$ 95,776
Agriculture [Member] \| Total Charge-Offs
Financing Receivable, Allowance for Credit Losses [Line Items]
2026	0
2025	0
2024	40
2023	0
2022	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Total	$ 40

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