Loans Held-for-Investment and Allowance for Credit Losses - Schedule of Past Due Loans (Detail) - USD ($) $ in Thousands		Jun. 30, 2025	Dec. 31, 2024	Jun. 30, 2024
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		$ 8,075,000	$ 7,914,000	$ 7,520,000
Total Loans		8,074,944	7,913,098	7,519,733
Total 90 Days Past Due Still Accruing		77	287	231
C&I [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,202,000	1,177,000	1,142,000
Total Loans		1,202,151	1,176,993	1,141,990
Municipal [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		306,000	369,000	359,000
Total Loans		306,140	369,246	359,124
Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,173,000	1,055,000	986,000
Total Loans		1,172,834	1,054,603	986,394
Farm [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		303,000	340,000	319,000
Total Loans		302,969	339,665	318,597
Non-Owner Occupied CRE [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		746,000	806,000	816,000
Total Loans		746,341	805,566	815,713
Owner Occupied CRE [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,125,000	1,083,000	1,050,000
Total Loans		1,124,610	1,083,100	1,049,715
Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		2,286,000	2,196,000	1,991,000
Total Loans		2,286,220	2,196,767	1,990,604
Auto [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		699,000	640,000	615,000
Total Loans		698,897	638,560	615,192
Non-Auto [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		149,000	153,000	156,000
Total Loans		148,649	153,055	156,218
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		1,508,291	1,546,239	1,501,114
Total 90 Days Past Due Still Accruing		0	258	0
Commercial [Member] | C&I [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		1,202,151	1,176,993	1,141,990
Total 90 Days Past Due Still Accruing			258
Commercial [Member] | Municipal [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		306,140	369,246	359,124
Agriculture [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		86,133	95,543	86,186
Total 90 Days Past Due Still Accruing		0		0
Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		5,632,974	5,479,701	5,161,023
Total 90 Days Past Due Still Accruing		77	29	95
Real Estate [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		1,172,834	1,054,603	986,394
Total 90 Days Past Due Still Accruing			0
Real Estate [Member] | Farm [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		302,969	339,665	318,597
Total 90 Days Past Due Still Accruing				95
Real Estate [Member] | Non-Owner Occupied CRE [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		746,341	805,566	815,713
Total 90 Days Past Due Still Accruing		77
Real Estate [Member] | Owner Occupied CRE [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		1,124,610	1,083,100	1,049,715
Real Estate [Member] | Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		2,286,220	2,196,767	1,990,604
Total 90 Days Past Due Still Accruing			29
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		847,546	791,615	771,410
Total 90 Days Past Due Still Accruing		0		136
Consumer [Member] | Auto [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		698,897	638,560	615,192
Total 90 Days Past Due Still Accruing				1
Consumer [Member] | Non-Auto [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans		148,649	153,055	156,218
Total 90 Days Past Due Still Accruing				135
15-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	28,277	32,543	41,142
15-59 Days Past Due [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	2,355	4,581	5,035
15-59 Days Past Due [Member] | Commercial [Member] | C&I [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	2,130	4,232	4,953
15-59 Days Past Due [Member] | Commercial [Member] | Municipal [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	225	349	82
15-59 Days Past Due [Member] | Agriculture [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	1,797	917	1,158
15-59 Days Past Due [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	22,586	25,681	33,532
15-59 Days Past Due [Member] | Real Estate [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	3,870	5,652	11,086
15-59 Days Past Due [Member] | Real Estate [Member] | Farm [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	805	433	2,055
15-59 Days Past Due [Member] | Real Estate [Member] | Non-Owner Occupied CRE [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	512	666	2,208
15-59 Days Past Due [Member] | Real Estate [Member] | Owner Occupied CRE [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	1,083	3,151	3,478
15-59 Days Past Due [Member] | Real Estate [Member] | Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	16,316	15,779	14,705
15-59 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	1,539	1,364	1,417
15-59 Days Past Due [Member] | Consumer [Member] | Auto [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	1,162	1,227	1,063
15-59 Days Past Due [Member] | Consumer [Member] | Non-Auto [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	377	137	354
60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		7,876	8,228	4,673
60-89 Days Past Due [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		2,710	3,974	593
60-89 Days Past Due [Member] | Commercial [Member] | C&I [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		2,710	3,938	593
60-89 Days Past Due [Member] | Commercial [Member] | Municipal [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due			36
60-89 Days Past Due [Member] | Agriculture [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due			10	997
60-89 Days Past Due [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		5,059	4,069	2,587
60-89 Days Past Due [Member] | Real Estate [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,878	564	1,144
60-89 Days Past Due [Member] | Real Estate [Member] | Farm [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due			1,128	0
60-89 Days Past Due [Member] | Real Estate [Member] | Non-Owner Occupied CRE [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		30		0
60-89 Days Past Due [Member] | Real Estate [Member] | Owner Occupied CRE [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		162	246	27
60-89 Days Past Due [Member] | Real Estate [Member] | Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		2,989	2,131	1,416
60-89 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		107	175	496
60-89 Days Past Due [Member] | Consumer [Member] | Auto [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		82	141	361
60-89 Days Past Due [Member] | Consumer [Member] | Non-Auto [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		25	34	135
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		9,855	8,043	4,685
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,322	1,368	1,060
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial [Member] | C&I [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,322	1,368	1,060
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Agriculture [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due			795	119
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		7,097	5,880	3,344
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,819	609	545
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate [Member] | Farm [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		823		95
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate [Member] | Non-Owner Occupied CRE [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,415	1,979	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate [Member] | Owner Occupied CRE [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,034	1,145	1,335
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate [Member] | Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		2,006	2,147	1,369
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		27	0	162
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer [Member] | Auto [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		22	0	13
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer [Member] | Non-Auto [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		5		149
Total Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		46,008	48,814	50,500
Total Past Due [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		6,387	9,923	6,688
Total Past Due [Member] | Commercial [Member] | C&I [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		6,162	9,538	6,606
Total Past Due [Member] | Commercial [Member] | Municipal [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		225	385	82
Total Past Due [Member] | Agriculture [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		3,206	1,722	2,274
Total Past Due [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		34,742	35,630	39,463
Total Past Due [Member] | Real Estate [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		7,567	6,825	12,775
Total Past Due [Member] | Real Estate [Member] | Farm [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,628	1,561	2,150
Total Past Due [Member] | Real Estate [Member] | Non-Owner Occupied CRE [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,957	2,645	2,208
Total Past Due [Member] | Real Estate [Member] | Owner Occupied CRE [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		2,279	4,542	4,840
Total Past Due [Member] | Real Estate [Member] | Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		21,311	20,057	17,490
Total Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,673	1,539	2,075
Total Past Due [Member] | Consumer [Member] | Auto [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,266	1,368	1,437
Total Past Due [Member] | Consumer [Member] | Non-Auto [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		407	171	638
Current [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		8,028,936	7,864,284	7,469,233
Current [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,501,904	1,536,316	1,494,426
Current [Member] | Commercial [Member] | C&I [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,195,989	1,167,455	1,135,384
Current [Member] | Commercial [Member] | Municipal [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		305,915	368,861	359,042
Current [Member] | Agriculture [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		82,927	93,821	83,912
Current [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		5,598,232	5,444,071	5,121,560
Current [Member] | Real Estate [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,165,267	1,047,778	973,619
Current [Member] | Real Estate [Member] | Farm [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		301,341	338,104	316,447
Current [Member] | Real Estate [Member] | Non-Owner Occupied CRE [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		744,384	802,921	813,505
Current [Member] | Real Estate [Member] | Owner Occupied CRE [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,122,331	1,078,558	1,044,875
Current [Member] | Real Estate [Member] | Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		2,264,909	2,176,710	1,973,114
Current [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		845,873	790,076	769,335
Current [Member] | Consumer [Member] | Auto [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		697,631	637,192	613,755
Current [Member] | Consumer [Member] | Non-Auto [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		$ 148,242	$ 152,884	$ 155,580

[1] The Company monitors commercial, agricultural and real estate loans after such loans are 15 days past due. Consumer loans are monitored after such loans are 30 days past due.