Loans and Allowance for Loan Losses - Schedule Of Current, Accruing Past Due And Nonaccrual Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	$ 43,309,877	$ 43,404,490
Non-accrual with an ALL	298,857	216,667
Non-accrual without an ALL	51,593	71,510
Accrued interest receivable	$ 248,000	$ 256,300
Financing receivable, accrued interest, after allowance for credit loss, statement of financial position [extensible enumeration]	Other assets	Other assets
Total commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	$ 22,731,296	$ 22,598,493
Non-accrual with an ALL	223,256	137,184
Non-accrual without an ALL	49,655	44,056
Total commercial and industrial | Commercial, financial and agricultural
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	14,616,902	14,459,345
Non-accrual with an ALL	173,435	66,400
Non-accrual without an ALL	19,258	23,470
Total commercial and industrial | Owner-occupied
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	8,114,394	8,139,148
Non-accrual with an ALL	49,821	70,784
Non-accrual without an ALL	30,397	20,586
Total commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	12,194,019	12,316,758
Non-accrual with an ALL	13,606	16,205
Non-accrual without an ALL	1,938	27,425
Total commercial real estate | Investment properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	11,310,881	11,363,304
Non-accrual with an ALL	10,630	12,796
Non-accrual without an ALL	1,596	26,974
Total commercial real estate | 1-4 family properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	580,138	598,502
Non-accrual with an ALL	1,958	2,605
Non-accrual without an ALL	342	451
Total commercial real estate | Land and development
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	303,000	354,952
Non-accrual with an ALL	1,018	804
Non-accrual without an ALL	0	0
Total consumer
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	8,384,562	8,489,239
Non-accrual with an ALL	61,995	63,278
Non-accrual without an ALL	0	29
Total consumer | Consumer mortgages
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	5,384,602	5,411,723
Non-accrual with an ALL	42,563	46,108
Non-accrual without an ALL	0	0
Total consumer | Home equity
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,804,348	1,807,399
Non-accrual with an ALL	12,451	10,473
Non-accrual without an ALL	0	0
Total consumer | Credit cards
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	180,663	194,141
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	1,014,949	1,075,976
Non-accrual with an ALL	6,981	6,697
Non-accrual without an ALL	0	29
Current
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	42,904,613	43,057,214
Current | Total commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	22,442,926	22,396,987
Current | Total commercial and industrial | Commercial, financial and agricultural
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	14,415,219	14,355,414
Current | Total commercial and industrial | Owner-occupied
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	8,027,707	8,041,573
Current | Total commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	12,176,939	12,271,352
Current | Total commercial real estate | Investment properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	11,298,410	11,322,516
Current | Total commercial real estate | 1-4 family properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	576,878	595,359
Current | Total commercial real estate | Land and development
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	301,651	353,477
Current | Total consumer
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	8,284,748	8,388,875
Current | Total consumer | Consumer mortgages
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	5,333,982	5,359,153
Current | Total consumer | Home equity
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,778,768	1,785,836
Current | Total consumer | Credit cards
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	177,054	190,299
Current | Total consumer | Other consumer loans
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	994,944	1,053,587
Accruing 30-89 Days Past Due
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	51,066	54,046
Accruing 30-89 Days Past Due | Total commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	13,635	18,320
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	7,323	12,264
Accruing 30-89 Days Past Due | Total commercial and industrial | Owner-occupied
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	6,312	6,056
Accruing 30-89 Days Past Due | Total commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,516	1,498
Accruing 30-89 Days Past Due | Total commercial real estate | Investment properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	245	740
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	940	87
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	331	671
Accruing 30-89 Days Past Due | Total consumer
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	35,915	34,228
Accruing 30-89 Days Past Due | Total consumer | Consumer mortgages
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	8,057	6,462
Accruing 30-89 Days Past Due | Total consumer | Home equity
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	13,129	10,374
Accruing 30-89 Days Past Due | Total consumer | Credit cards
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,705	1,818
Accruing 30-89 Days Past Due | Total consumer | Other consumer loans
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	13,024	15,574
Accruing 90 Days or Greater Past Due
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	3,748	5,053
Accruing 90 Days or Greater Past Due | Total commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,824	1,946
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	1,667	1,797
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	157	149
Accruing 90 Days or Greater Past Due | Total commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	20	278
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	0	278
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	20	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	0
Accruing 90 Days or Greater Past Due | Total consumer
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,904	2,829
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	0	716
Accruing 90 Days or Greater Past Due | Total consumer | Credit cards
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,904	2,024
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	89
Total Accruing Past Due
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	54,814	59,099
Total Accruing Past Due | Total commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	15,459	20,266
Total Accruing Past Due | Total commercial and industrial | Commercial, financial and agricultural
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	8,990	14,061
Total Accruing Past Due | Total commercial and industrial | Owner-occupied
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	6,469	6,205
Total Accruing Past Due | Total commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,536	1,776
Total Accruing Past Due | Total commercial real estate | Investment properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	245	1,018
Total Accruing Past Due | Total commercial real estate | 1-4 family properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	960	87
Total Accruing Past Due | Total commercial real estate | Land and development
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	331	671
Total Accruing Past Due | Total consumer
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	37,819	37,057
Total Accruing Past Due | Total consumer | Consumer mortgages
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	8,057	6,462
Total Accruing Past Due | Total consumer | Home equity
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	13,129	11,090
Total Accruing Past Due | Total consumer | Credit cards
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	3,609	3,842
Total Accruing Past Due | Total consumer | Other consumer loans
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	$ 13,024	$ 15,663