Loans and Allowance for Loan Losses - Schedule of Current, Accruing Past Due, and Non-Accrual Loans by Portfolio Class (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	$ 42,648,738	$ 42,609,028
Non-accrual with an ALL	254,835	271,174
Non-accrual without an ALL	31,794	37,990
Accrued interest receivable	$ 215,300	$ 217,100
Financing receivable, accrued interest, after allowance for credit loss, statement of financial position [extensible enumeration]	Other assets	Other assets
Deferred loan costs (fees)	$ (32,600)	$ (34,100)
Total commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	22,313,339	22,331,129
Non-accrual with an ALL	113,820	119,264
Non-accrual without an ALL	29,976	37,990
Total commercial and industrial \| Commercial, financial and agricultural
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	14,611,712	14,498,992
Non-accrual with an ALL	103,206	98,145
Non-accrual without an ALL	22,364	24,729
Total commercial and industrial \| Owner-occupied
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	7,701,627	7,832,137
Non-accrual with an ALL	10,614	21,119
Non-accrual without an ALL	7,612	13,261
Total commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	12,071,558	12,014,619
Non-accrual with an ALL	70,064	77,804
Non-accrual without an ALL	0	0
Total commercial real estate \| Investment properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	11,265,901	11,181,204
Non-accrual with an ALL	66,076	74,030
Non-accrual without an ALL	0	0
Total commercial real estate \| 1-4 family properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	513,438	545,918
Non-accrual with an ALL	2,577	2,385
Non-accrual without an ALL	0	0
Total commercial real estate \| Land and development
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	292,219	287,497
Non-accrual with an ALL	1,411	1,389
Non-accrual without an ALL	0	0
Total consumer
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	8,263,841	8,263,280
Non-accrual with an ALL	70,951	74,106
Non-accrual without an ALL	1,818	0
Total consumer \| Consumer mortgages
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	5,269,505	5,288,776
Non-accrual with an ALL	47,223	50,834
Non-accrual without an ALL	1,636	0
Total consumer \| Home equity
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,839,185	1,831,287
Non-accrual with an ALL	18,120	17,365
Non-accrual without an ALL	182	0
Total consumer \| Credit cards
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	178,522	185,871
Non-accrual with an ALL	0	0
Non-accrual without an ALL	0	0
Total consumer \| Other consumer loans
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	976,629	957,346
Non-accrual with an ALL	5,608	5,907
Non-accrual without an ALL	0	0
Current
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	42,268,616	42,190,986
Current \| Total commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	22,112,953	22,106,891
Current \| Total commercial and industrial \| Commercial, financial and agricultural
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	14,471,969	14,352,839
Current \| Total commercial and industrial \| Owner-occupied
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	7,640,984	7,754,052
Current \| Total commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	11,998,624	11,931,858
Current \| Total commercial real estate \| Investment properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	11,197,739	11,105,168
Current \| Total commercial real estate \| 1-4 family properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	510,077	541,897
Current \| Total commercial real estate \| Land and development
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	290,808	284,793
Current \| Total consumer
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	8,157,039	8,152,237
Current \| Total consumer \| Consumer mortgages
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	5,212,156	5,228,580
Current \| Total consumer \| Home equity
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,808,427	1,800,614
Current \| Total consumer \| Credit cards
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	175,030	182,435
Current \| Total consumer \| Other consumer loans
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	961,426	940,608
Accruing 30-89 Days Past Due
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	52,607	60,286
Accruing 30-89 Days Past Due \| Total commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	17,773	20,647
Accruing 30-89 Days Past Due \| Total commercial and industrial \| Commercial, financial and agricultural
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	12,271	12,947
Accruing 30-89 Days Past Due \| Total commercial and industrial \| Owner-occupied
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	5,502	7,700
Accruing 30-89 Days Past Due \| Total commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	2,642	4,755
Accruing 30-89 Days Past Due \| Total commercial real estate \| Investment properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,858	2,006
Accruing 30-89 Days Past Due \| Total commercial real estate \| 1-4 family properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	784	1,636
Accruing 30-89 Days Past Due \| Total commercial real estate \| Land and development
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	0	1,113
Accruing 30-89 Days Past Due \| Total consumer
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	32,192	34,884
Accruing 30-89 Days Past Due \| Total consumer \| Consumer mortgages
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	8,490	9,362
Accruing 30-89 Days Past Due \| Total consumer \| Home equity
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	12,357	13,131
Accruing 30-89 Days Past Due \| Total consumer \| Credit cards
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,750	1,573
Accruing 30-89 Days Past Due \| Total consumer \| Other consumer loans
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	9,595	10,818
Accruing 90 Days or Greater Past Due
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	40,886	48,592
Accruing 90 Days or Greater Past Due \| Total commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	38,817	46,337
Accruing 90 Days or Greater Past Due \| Total commercial and industrial \| Commercial, financial and agricultural
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,902	10,332
Accruing 90 Days or Greater Past Due \| Total commercial and industrial \| Owner-occupied
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	36,915	36,005
Accruing 90 Days or Greater Past Due \| Total commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	228	202
Accruing 90 Days or Greater Past Due \| Total commercial real estate \| Investment properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	228	0
Accruing 90 Days or Greater Past Due \| Total commercial real estate \| 1-4 family properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	0	0
Accruing 90 Days or Greater Past Due \| Total commercial real estate \| Land and development
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	0	202
Accruing 90 Days or Greater Past Due \| Total consumer
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,841	2,053
Accruing 90 Days or Greater Past Due \| Total consumer \| Consumer mortgages
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	0	0
Accruing 90 Days or Greater Past Due \| Total consumer \| Home equity
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	99	177
Accruing 90 Days or Greater Past Due \| Total consumer \| Credit cards
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,742	1,863
Accruing 90 Days or Greater Past Due \| Total consumer \| Other consumer loans
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	0	13
Total Accruing Past Due
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	93,493	108,878
Total Accruing Past Due \| Total commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	56,590	66,984
Total Accruing Past Due \| Total commercial and industrial \| Commercial, financial and agricultural
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	14,173	23,279
Total Accruing Past Due \| Total commercial and industrial \| Owner-occupied
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	42,417	43,705
Total Accruing Past Due \| Total commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	2,870	4,957
Total Accruing Past Due \| Total commercial real estate \| Investment properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	2,086	2,006
Total Accruing Past Due \| Total commercial real estate \| 1-4 family properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	784	1,636
Total Accruing Past Due \| Total commercial real estate \| Land and development
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	0	1,315
Total Accruing Past Due \| Total consumer
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	34,033	36,937
Total Accruing Past Due \| Total consumer \| Consumer mortgages
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	8,490	9,362
Total Accruing Past Due \| Total consumer \| Home equity
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	12,456	13,308
Total Accruing Past Due \| Total consumer \| Credit cards
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	3,492	3,436
Total Accruing Past Due \| Total consumer \| Other consumer loans
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	$ 9,595	$ 10,831

Loans and Allowance for Loan Losses - Schedule of Current, Accruing Past Due, and Non-Accrual Loans by Portfolio Class (Details) - USD ($)
$ in Thousands