v3.20.4
Allowance For Credit Losses (Analysis Of The Allowance For Credit Losses By Portfolio Segment) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Allowance for Loan and Lease Losses [Roll Forward]      
Allowance for loan losses, beginning of period $ 869 $ 840 $ 934
Cumulative change in accounting guidance 438    
Allowance for loan losses, beginning of period as adjusted for CECL 1,307    
Provision (credit) for loan losses 1,312 387 229
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase 60    
Loan Losses:      
Charge-offs (613) (443) (433)
Recoveries 101 85 110
Net loan losses (512) (358) (323)
Total allowance for loan losses 2,167 869 840
Reserve For Unfunded Credit Commitments [Roll Forward]      
Reserve for unfunded credit commitments, beginning of year 45 51 53
Provision (credit) for unfunded credit losses 18 (6) (2)
Reserve for unfunded credit commitments, end of year 126 45 51
Allowance for Credit Losses, end of period 2,293 914 891
UnfundedcreditcommitmentsChangeinAccountingGuidance 63    
Reserve For Unfunded Credit Commitments Beginning Balance as adjusted for CECL 108    
Portion of ending allowance for loan losses:      
Individually evaluated for impairment   153 132
Collectively evaluated for impairment   716 708
Total allowance for loan losses 2,167 869 840
Portion of loan portfolio ending balance:      
Individually evaluated for impairment   952 934
Collectively evaluated for impairment   82,011 82,218
Loans, net of unearned income 85,266 82,963 83,152
Commercial Portfolio Segment [Member]      
Allowance for Loan and Lease Losses [Roll Forward]      
Allowance for loan losses, beginning of period 537 520 591
Cumulative change in accounting guidance (3)    
Allowance for loan losses, beginning of period as adjusted for CECL 534    
Provision (credit) for loan losses 927 138 32
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase 60    
Loan Losses:      
Charge-offs (368) (150) (148)
Recoveries 43 29 45
Net loan losses (325) (121) (103)
Total allowance for loan losses 1,196 537 520
Reserve For Unfunded Credit Commitments [Roll Forward]      
Reserve for unfunded credit commitments, beginning of year 41 47 49
Provision (credit) for unfunded credit losses 20 (6) (2)
Reserve for unfunded credit commitments, end of year 97 41 47
Allowance for Credit Losses, end of period 1,293 578 567
UnfundedcreditcommitmentsChangeinAccountingGuidance 36    
Reserve For Unfunded Credit Commitments Beginning Balance as adjusted for CECL 77    
Portion of ending allowance for loan losses:      
Individually evaluated for impairment   120 104
Collectively evaluated for impairment   417 416
Total allowance for loan losses 1,196 537 520
Portion of loan portfolio ending balance:      
Individually evaluated for impairment   537 490
Collectively evaluated for impairment   45,302 44,725
Loans, net of unearned income 48,575 45,839 45,215
Total Investor Real Estate [Member]      
Allowance for Loan and Lease Losses [Roll Forward]      
Allowance for loan losses, beginning of period 45 58 64
Cumulative change in accounting guidance 7    
Allowance for loan losses, beginning of period as adjusted for CECL 52    
Provision (credit) for loan losses 129 (16) (5)
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase 0    
Loan Losses:      
Charge-offs (1) (1) (9)
Recoveries 3 4 8
Net loan losses 2 3 (1)
Total allowance for loan losses 183 45 58
Reserve For Unfunded Credit Commitments [Roll Forward]      
Reserve for unfunded credit commitments, beginning of year 4 4 4
Provision (credit) for unfunded credit losses (3) 0 0
Reserve for unfunded credit commitments, end of year 14 4 4
Allowance for Credit Losses, end of period 197 49 62
UnfundedcreditcommitmentsChangeinAccountingGuidance 13    
Reserve For Unfunded Credit Commitments Beginning Balance as adjusted for CECL 17    
Portion of ending allowance for loan losses:      
Individually evaluated for impairment   4 2
Collectively evaluated for impairment   41 56
Total allowance for loan losses 183 45 58
Portion of loan portfolio ending balance:      
Individually evaluated for impairment   34 25
Collectively evaluated for impairment   6,523 6,411
Loans, net of unearned income 7,263 6,557 6,436
Consumer Portfolio Segment [Member]      
Allowance for Loan and Lease Losses [Roll Forward]      
Allowance for loan losses, beginning of period 287 262 279
Cumulative change in accounting guidance 434    
Allowance for loan losses, beginning of period as adjusted for CECL 721    
Provision (credit) for loan losses 256 265 202
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase 0    
Loan Losses:      
Charge-offs (244) (292) (276)
Recoveries 55 52 57
Net loan losses (189) (240) (219)
Total allowance for loan losses 788 287 262
Reserve For Unfunded Credit Commitments [Roll Forward]      
Reserve for unfunded credit commitments, beginning of year 0 0 0
Provision (credit) for unfunded credit losses 1 0 0
Reserve for unfunded credit commitments, end of year 15 0 0
Allowance for Credit Losses, end of period 803 287 262
UnfundedcreditcommitmentsChangeinAccountingGuidance 14    
Reserve For Unfunded Credit Commitments Beginning Balance as adjusted for CECL 14    
Portion of ending allowance for loan losses:      
Individually evaluated for impairment   29 26
Collectively evaluated for impairment   258 236
Total allowance for loan losses 788 287 262
Portion of loan portfolio ending balance:      
Individually evaluated for impairment   381 419
Collectively evaluated for impairment   30,186 31,082
Loans, net of unearned income $ 29,428 $ 30,567 $ 31,501