v3.26.3
LOANS AND ALLOWANCE FOR CREDIT LOSSES - Schedule of Activity in ACL by Portfolio Segment (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Allowance for Loan Losses [Roll Forward]          
ALLL, beginning of period $ 5,819 $ 6,357 $ 6,000 $ 6,562 $ 6,562
Day 1 allowance on purchased loans at acquisition 856 0 895 0  
Credit loss expense / (benefit) 570 372 1,268 1,165  
Charge-offs (1,198) (1,200) (3,435) (3,477)  
Recoveries 650 620 1,969 1,899  
Charge-offs, net of recoveries (548) (580) (1,466) (1,578)  
ALLL, end of period 6,697 6,149 6,697 6,149 6,000
Reserve for Unfunded Lending Commitments Roll Forward [Roll Forward]          
Reserve for unfunded lending commitments, beginning of period 34 54 53 48 48
Credit loss expense/ (benefit) on unfunded lending commitments 31 (4) 12 2  
Reserve for unfunded lending commitments, end of period 65 50 65 50 53
Total ACL, end of period 6,762 6,199 6,762 6,199  
Commercial          
Allowance for Loan Losses [Roll Forward]          
ALLL, beginning of period 461 523 472 566 566
Day 1 allowance on purchased loans at acquisition 770 0 770 0  
Credit loss expense / (benefit) 70 (7) 93 3  
Charge-offs (62) (37) (112) (118) (144)
Recoveries 9 11 25 39  
Charge-offs, net of recoveries (53) (26) (87) (79)  
ALLL, end of period 1,248 490 1,248 490 472
Reserve for Unfunded Lending Commitments Roll Forward [Roll Forward]          
Reserve for unfunded lending commitments, beginning of period 25 43 43 46 46
Credit loss expense/ (benefit) on unfunded lending commitments 31 (3) 13 (6)  
Reserve for unfunded lending commitments, end of period 56 40 56 40 43
Total ACL, end of period 1,304 530 1,304 530  
Consumer          
Allowance for Loan Losses [Roll Forward]          
ALLL, beginning of period 5,358 5,834 5,528 5,996 5,996
Day 1 allowance on purchased loans at acquisition 86 0 125 0  
Credit loss expense / (benefit) 500 379 1,175 1,162  
Charge-offs (1,136) (1,163) (3,323) (3,359)  
Recoveries 641 609 1,944 1,860  
Charge-offs, net of recoveries (495) (554) (1,379) (1,499)  
ALLL, end of period 5,449 5,659 5,449 5,659 5,528
Reserve for Unfunded Lending Commitments Roll Forward [Roll Forward]          
Reserve for unfunded lending commitments, beginning of period 9 11 10 2 2
Credit loss expense/ (benefit) on unfunded lending commitments 0 (1) (1) 8  
Reserve for unfunded lending commitments, end of period 9 10 9 10 $ 10
Total ACL, end of period $ 5,458 $ 5,669 $ 5,458 $ 5,669