Loans and Allowance for Loan Losses (Schedule of Current, Accruing Past Due and Nonaccrual Loans) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	$ 44,353,537	$ 43,716,353
Non-accrual with an ALL	217,702	113,519
Non-accrual without an ALL	43,804	14,542
Total commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	22,531,232	22,066,656
Non-accrual with an ALL	125,331	57,507
Non-accrual without an ALL	41,281	11,904
Total commercial and industrial | Commercial, financial and agricultural
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	14,166,890	13,874,416
Non-accrual with an ALL	119,134	48,008
Non-accrual without an ALL	25,281	11,299
Total commercial and industrial | Owner-occupied
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	8,364,342	8,192,240
Non-accrual with an ALL	6,197	9,499
Non-accrual without an ALL	16,000	605
Total consumer
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	8,528,407	8,999,384
Non-accrual with an ALL	58,215	50,897
Non-accrual without an ALL	31	0
Total consumer | Consumer mortgages
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	5,379,284	5,214,443
Non-accrual with an ALL	41,877	36,847
Non-accrual without an ALL	0	0
Total consumer | Home equity
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,773,987	1,757,038
Non-accrual with an ALL	9,936	6,830
Non-accrual without an ALL	0	0
Total consumer | Credit cards
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	187,677	203,612
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	1,187,459	1,824,291
Non-accrual with an ALL	6,402	7,220
Non-accrual without an ALL	31	0
Total commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	13,293,898	12,650,313
Non-accrual with an ALL	34,156	5,115
Non-accrual without an ALL	2,492	2,638
Total commercial real estate | Investment properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	12,270,266	11,644,047
Non-accrual with an ALL	29,692	1,785
Non-accrual without an ALL	1,661	1,688
Total commercial real estate | 1-4 family properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	615,726	616,933
Non-accrual with an ALL	3,326	2,172
Non-accrual without an ALL	831	950
Total commercial real estate | Land and development
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	407,906	389,333
Non-accrual with an ALL	1,138	1,158
Non-accrual without an ALL	0	0
Current
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	44,007,085	43,522,724
Current | Total commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	22,316,379	21,980,288
Current | Total commercial and industrial | Commercial, financial and agricultural
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	14,001,859	13,798,639
Current | Total commercial and industrial | Owner-occupied
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	8,314,520	8,181,649
Current | Total consumer
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	8,437,117	8,901,675
Current | Total consumer | Consumer mortgages
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	5,332,966	5,163,417
Current | Total consumer | Home equity
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,757,068	1,742,412
Current | Total consumer | Credit cards
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	184,145	200,047
Current | Total consumer | Other consumer loans
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,162,938	1,795,799
Current | Total commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	13,253,589	12,640,761
Current | Total commercial real estate | Investment properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	12,236,317	11,639,614
Current | Total commercial real estate | 1-4 family properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	610,704	613,049
Current | Total commercial real estate | Land and development
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	406,568	388,098
Accruing 30-89 Days Past Due
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	81,303	62,195
Accruing 30-89 Days Past Due | Total commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	46,759	15,520
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	19,134	15,033
Accruing 30-89 Days Past Due | Total commercial and industrial | Owner-occupied
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	27,625	487
Accruing 30-89 Days Past Due | Total consumer
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	30,883	44,876
Accruing 30-89 Days Past Due | Total consumer | Consumer mortgages
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	4,441	13,969
Accruing 30-89 Days Past Due | Total consumer | Home equity
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	6,983	7,795
Accruing 30-89 Days Past Due | Total consumer | Credit cards
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,481	1,843
Accruing 30-89 Days Past Due | Total consumer | Other consumer loans
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	17,978	21,269
Accruing 30-89 Days Past Due | Total commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	3,661	1,799
Accruing 30-89 Days Past Due | Total commercial real estate | Investment properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	2,596	960
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	865	762
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	200	77
Accruing 90 Days or Greater Past Due
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	3,643	3,373
Accruing 90 Days or Greater Past Due | Total commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	1,482	1,437
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	1,482	1,437
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	0	0
Accruing 90 Days or Greater Past Due | Total consumer
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	2,161	1,936
Accruing 90 Days or Greater Past Due | Total consumer | Consumer mortgages
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	0	210
Accruing 90 Days or Greater Past Due | Total consumer | Home equity
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	0	1
Accruing 90 Days or Greater Past Due | Total consumer | Credit cards
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	2,051	1,722
Accruing 90 Days or Greater Past Due | Total consumer | Other consumer loans
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	110	3
Accruing 90 Days or Greater Past Due | Total commercial real estate
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 | Investment 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 | 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	0
Total Accruing Past Due
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	84,946	65,568
Total Accruing Past Due | Total commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	48,241	16,957
Total Accruing Past Due | Total commercial and industrial | Commercial, financial and agricultural
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	20,616	16,470
Total Accruing Past Due | Total commercial and industrial | Owner-occupied
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	27,625	487
Total Accruing Past Due | Total consumer
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	33,044	46,812
Total Accruing Past Due | Total consumer | Consumer mortgages
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	4,441	14,179
Total Accruing Past Due | Total consumer | Home equity
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	6,983	7,796
Total Accruing Past Due | Total consumer | Credit cards
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	3,532	3,565
Total Accruing Past Due | Total consumer | Other consumer loans
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	18,088	21,272
Total Accruing Past Due | Total commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	3,661	1,799
Total Accruing Past Due | Total commercial real estate | Investment properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	2,596	960
Total Accruing Past Due | Total commercial real estate | 1-4 family properties
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	865	762
Total Accruing Past Due | Total commercial real estate | Land and development
Financing Receivable, Nonaccrual [Line Items]
Loans, net of deferred fees and costs	$ 200	$ 77