Quarterly report [Sections 13 or 15(d)]

Outstanding Loans and Leases and Allowance for Credit Losses - Allowance for Credit Losses (Details)

v3.25.1
Outstanding Loans and Leases and Allowance for Credit Losses - Allowance for Credit Losses (Details) - USD ($)
$ in Millions
 3 Months Ended 15 Months Ended
Dec. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Mar. 31, 2024
Dec. 31, 2026
Financing Receivable, Allowance for Credit Loss [Line Items]          
Allowance for credit losses, period increase (decrease)     $ 30    
Allowance for credit losses     14,366 $ 14,371  
Loan and leases receivable, allowance, period increase     16    
Reserve for unfunded lending commitments, period increase     14    
Increase in provision for credit losses     161    
Provision (benefit) for credit losses     1,480 1,319  
Outstanding loans and leases, period increase, excluding loans accounted for under the fair value option     13,700    
Scenario, Forecast          
Financing Receivable, Allowance for Credit Loss [Line Items]          
Unemployment rate, current economic outlook (just below)         5.00%
U.S. gross domestic product, current economic outlook 1.70% 1.00%      
Commercial          
Financing Receivable, Allowance for Credit Loss [Line Items]          
Allowance for credit losses, period increase (decrease)     48    
Allowance for credit losses     5,757 5,838  
Outstanding loans and leases, period increase, excluding loans accounted for under the fair value option     10,600    
Consumer real estate          
Financing Receivable, Allowance for Credit Loss [Line Items]          
Allowance for credit losses, period increase (decrease)     47    
Allowance for credit losses     397 412  
Outstanding loans and leases, period increase, excluding loans accounted for under the fair value option     7,000    
Credit card and other consumer          
Financing Receivable, Allowance for Credit Loss [Line Items]          
Allowance for credit losses, period increase (decrease)     (65)    
Allowance for credit losses     8,212 $ 8,121  
Outstanding loans and leases, period increase, excluding loans accounted for under the fair value option     $ (3,800)