Loans and Allowance for Credit Losses - Allowance for Credit Losses on Loans by Category of Loan (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses on loans, beginning balance	$ 346,084	$ 359,852	$ 351,805	$ 332,362
Initial allowance on loans purchased with credit deterioration				26,078
Provision for credit losses	0		0	7,923
Charge-offs	(7,512)	(6,540)	(15,678)	(16,259)
Recoveries	1,054	1,085	3,499	4,293
Net (charge-offs) recoveries	(6,458)	(5,455)	(12,179)	(11,966)
Allowance for credit losses on loans, ending balance	339,626	354,397	339,626	354,397
Real Estate [Member] \| Construction, Land Development and Other Land Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses on loans, beginning balance	77,818	76,776	77,984	87,775
Initial allowance on loans purchased with credit deterioration				942
Provision for credit losses	(520)	(633)	(845)	(12,467)
Charge-offs	(166)	(378)	(247)	(486)
Recoveries	132		372	1
Net (charge-offs) recoveries	(34)	(378)	125	(485)
Allowance for credit losses on loans, ending balance	77,264	75,765	77,264	75,765
Real Estate [Member] \| Agriculture [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses on loans, beginning balance	26,848	29,479	27,693	11,380
Initial allowance on loans purchased with credit deterioration				14,309
Provision for credit losses	(3,083)	(450)	(3,942)	3,577
Charge-offs	(10)	(109)	(47)	(631)
Recoveries	50	225	101	510
Net (charge-offs) recoveries	40	116	54	(121)
Allowance for credit losses on loans, ending balance	23,805	29,145	23,805	29,145
Real Estate [Member] \| 1-4 Family [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses on loans, beginning balance	82,105	80,689	80,735	77,652
Initial allowance on loans purchased with credit deterioration				344
Provision for credit losses	(700)	1,442	2,063	5,017
Charge-offs	(861)	(442)	(2,329)	(1,336)
Recoveries	8	33	83	45
Net (charge-offs) recoveries	(853)	(409)	(2,246)	(1,291)
Allowance for credit losses on loans, ending balance	80,552	81,722	80,552	81,722
Real Estate [Member] \| Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses on loans, beginning balance	89,121	95,728	92,147	88,664
Initial allowance on loans purchased with credit deterioration				4,306
Provision for credit losses	(4,892)	(921)	(7,685)	1,439
Charge-offs	(1,102)	(297)	(1,601)	(808)
Recoveries	87	39	353	948
Net (charge-offs) recoveries	(1,015)	(258)	(1,248)	140
Allowance for credit losses on loans, ending balance	83,214	94,549	83,214	94,549
Commercial and Industrial [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses on loans, beginning balance	62,256	70,112	65,500	59,832
Initial allowance on loans purchased with credit deterioration				6,176
Provision for credit losses	8,216	(2,216)	6,346	4,948
Charge-offs	(3,804)	(3,746)	(6,382)	(8,283)
Recoveries	463	437	1,667	1,914
Net (charge-offs) recoveries	(3,341)	(3,309)	(4,715)	(6,369)
Allowance for credit losses on loans, ending balance	67,131	64,587	67,131	64,587
Consumer and Other [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses on loans, beginning balance	7,936	7,068	7,746	7,059
Initial allowance on loans purchased with credit deterioration				1
Provision for credit losses	979	2,778	4,063	5,409
Charge-offs	(1,569)	(1,568)	(5,072)	(4,715)
Recoveries	314	351	923	875
Net (charge-offs) recoveries	(1,255)	(1,217)	(4,149)	(3,840)
Allowance for credit losses on loans, ending balance	$ 7,660	$ 8,629	$ 7,660	$ 8,629