Allowance for Credit Losses - Roll Forward Of the Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Allowance for credit losses:
Beginning balance	$ 203,931	$ 201,052	$ 201,756	$ 198,578	$ 198,578
Charge-offs	(12,979)	(6,372)	(14,108)	(7,282)	(13,809)
Recoveries	925	891	2,179	1,637
Net charge-offs	(12,054)	(5,481)	(11,929)	(5,645)
Provision for (recovery of) credit losses on loans	75,400	4,300	77,450	6,938
Ending balance	290,770	199,871	290,770	199,871	201,756
Individually evaluated	27,935	10,004	27,935	10,004
Collectively evaluated	262,835	189,867	262,835	189,867
Loans:
Individually evaluated	107,318	54,002	107,318	54,002
Collectively evaluated	18,456,129	12,550,753	18,456,129	12,550,753
Loans, net of unearned income	18,563,447	12,604,755	18,563,447	12,604,755	12,885,020
Nonaccruing loans with no allowance for credit losses	21,868	27,188	21,868	27,188
Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses:
Beginning balance	23,493		23,493	0	0
Ending balance					23,493
Commercial, financial, agricultural
Allowance for credit losses:
Beginning balance	38,441	45,921	38,527	43,980	43,980
Charge-offs	(5,823)	(186)	(5,917)	(535)	(4,463)
Recoveries	627	525	1,585	871
Net charge-offs	(5,196)	339	(4,332)	336
Provision for (recovery of) credit losses on loans	19,291	(1,309)	18,341	635
Ending balance	59,676	44,951	59,676	44,951	38,527
Individually evaluated	9,604	8,514	9,604	8,514
Collectively evaluated	50,072	36,437	50,072	36,437
Loans:
Individually evaluated	20,316	14,211	20,316	14,211
Collectively evaluated	2,646,607	1,833,551	2,646,607	1,833,551
Loans, net of unearned income	2,666,923	1,847,762	2,666,923	1,847,762
Nonaccruing loans with no allowance for credit losses	0	230	0	230
Commercial, financial, agricultural \| Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses:
Beginning balance	7,140		7,140	0	0
Ending balance					7,140
Real estate – construction:
Allowance for credit losses:
Beginning balance	16,561	17,317	15,126	18,612	18,612
Charge-offs	(105)	0	(105)	0
Recoveries	0	0	0	0
Net charge-offs	(105)	0	(105)	0
Provision for (recovery of) credit losses on loans	3,331	1,579	4,766	284
Ending balance	21,784	18,896	21,784	18,896	15,126
Individually evaluated	1,993	0	1,993	0
Collectively evaluated	19,791	18,896	19,791	18,896
Loans:
Individually evaluated	16,045	0	16,045	0
Collectively evaluated	1,323,922	1,355,425	1,323,922	1,355,425
Loans, net of unearned income	1,339,967	1,355,425	1,339,967	1,355,425
Nonaccruing loans with no allowance for credit losses	2,332	0	2,332	0
Real estate – construction: \| Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses:
Beginning balance	1,997		1,997	0	0
Ending balance					1,997
Real estate – 1-4 family mortgage:
Allowance for credit losses:
Beginning balance	50,711	47,566	47,761	47,283	47,283
Charge-offs	(319)	(208)	(628)	(290)	(966)
Recoveries	37	25	70	73
Net charge-offs	(282)	(183)	(558)	(217)
Provision for (recovery of) credit losses on loans	15,010	38	18,236	355
Ending balance	65,703	47,421	65,703	47,421	47,761
Individually evaluated	0	0	0	0
Collectively evaluated	65,703	47,421	65,703	47,421
Loans:
Individually evaluated	4,776	6,942	4,776	6,942
Collectively evaluated	4,869,903	3,428,876	4,869,903	3,428,876
Loans, net of unearned income	4,874,679	3,435,818	4,874,679	3,435,818
Nonaccruing loans with no allowance for credit losses	4,275	6,318	4,275	6,318
Real estate – 1-4 family mortgage: \| Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses:
Beginning balance	264		264	0	0
Ending balance					264
Real estate – commercial mortgage:
Allowance for credit losses:
Beginning balance	88,080	78,725	90,204	77,020	77,020
Charge-offs	(3,944)	(5,727)	(4,405)	(5,727)	(5,737)
Recoveries	116	99	122	105
Net charge-offs	(3,828)	(5,628)	(4,283)	(5,622)
Provision for (recovery of) credit losses on loans	37,230	4,028	35,561	5,727
Ending balance	135,572	77,125	135,572	77,125	90,204
Individually evaluated	16,068	1,220	16,068	1,220
Collectively evaluated	119,504	75,905	119,504	75,905
Loans:
Individually evaluated	65,012	32,579	65,012	32,579
Collectively evaluated	9,405,122	5,733,899	9,405,122	5,733,899
Loans, net of unearned income	9,470,134	5,766,478	9,470,134	5,766,478
Nonaccruing loans with no allowance for credit losses	14,362	20,640	14,362	20,640
Real estate – commercial mortgage: \| Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses:
Beginning balance	14,090		14,090	0	0
Ending balance					14,090
Lease financing
Allowance for credit losses:
Beginning balance	3,644	2,554	3,368	2,515	2,515
Charge-offs	(2,394)	0	(2,394)	0	(642)
Recoveries	4	10	13	18
Net charge-offs	(2,390)	10	(2,381)	18
Provision for (recovery of) credit losses on loans	681	(49)	948	(18)
Ending balance	1,935	2,515	1,935	2,515	3,368
Individually evaluated	0	0	0	0
Collectively evaluated	1,935	2,515	1,935	2,515
Loans:
Individually evaluated	899	0	899	0
Collectively evaluated	88,669	102,996	88,669	102,996
Loans, net of unearned income	89,568	102,996	89,568	102,996
Nonaccruing loans with no allowance for credit losses	899	0	899	0
Lease financing \| Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses:
Beginning balance	0		0	0	0
Ending balance					0
Installment Loans to Individuals
Allowance for credit losses:
Beginning balance	6,494	8,969	6,770	9,168	9,168
Charge-offs	(394)	(251)	(659)	(730)	(1,856)
Recoveries	141	232	389	570
Net charge-offs	(253)	(19)	(270)	(160)
Provision for (recovery of) credit losses on loans	(143)	13	(402)	(45)
Ending balance	6,100	8,963	6,100	8,963	6,770
Individually evaluated	270	270	270	270
Collectively evaluated	5,830	8,693	5,830	8,693
Loans:
Individually evaluated	270	270	270	270
Collectively evaluated	121,906	96,006	121,906	96,006
Loans, net of unearned income	122,176	96,276	122,176	96,276
Nonaccruing loans with no allowance for credit losses	0	$ 0	0	0
Installment Loans to Individuals \| Cumulative Effect, Period Of Adoption, Adjustment
Allowance for credit losses:
Beginning balance	$ 2		$ 2	$ 0	0
Ending balance					$ 2

Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

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Amount of allowance for credit loss on financing receivable evaluated on collective basis. Excludes financing receivable evaluated on individual basis.

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Amount of allowance for credit loss on financing receivable evaluated on individual basis. Excludes financing receivable evaluated on collective basis.

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Amount of financing receivable collectively evaluated for credit loss. Excludes financing receivable individually evaluated for credit loss.

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Amount, excluding accrued interest, of increase in allowance for credit loss on financing receivable from recovery. Excludes net investment in lease.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease.

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Amount, excluding accrued interest, of decrease (increase) in allowance for credit loss on financing receivable from writeoff (recovery). Excludes net investment in lease.

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Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

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Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease.

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Amortized cost excluding accrued interest, of financing receivable on nonaccrual status with no allowance for credit loss. Excludes net investment in lease.

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Amount of financing receivable individually evaluated for credit loss. Excludes financing receivable collectively evaluated for credit loss.

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