v3.26.1
Fair Value Measurements, Fair Value Estimates for Financial Instruments (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Financial assets    
Cash and due from banks $ 33,543 $ 39,182
Interest-earning deposits with banks 141,241 135,028
Federal funds sold and securities borrowed or purchased under resale agreements 215,599 193,929
Held-to-maturity debt securities 204,080 208,023
Financial liabilities    
Federal funds purchased and securities loaned or sold under repurchase agreements 234,371 232,687
Short-term borrowings 32,282 18,323
Carrying value [Member]    
Financial assets    
Cash and due from banks 33,543 39,182
Interest-earning deposits with banks 141,241 135,028
Federal funds sold and securities borrowed or purchased under resale agreements 215,599 193,929
Held-to-maturity debt securities 204,080 208,023
Loans held for sale 3,740 2,618
Loans, net 987,622 957,037
Equity securities (cost method) 4,955 4,323
Total financial assets 1,590,780 1,540,140
Financial liabilities    
Deposits 189,154 166,686
Federal funds purchased and securities loaned or sold under repurchase agreements 234,371 232,687
Short-term borrowings 32,282 18,323
Long-term debt 174,532 167,618
Total financial liabilities 630,339 585,314
Fair Value Disclosures, Textual [Abstract]    
Lease financing, net 15,300 16,400
Deposit liabilities with no defined or contractual maturity 1,300,000 1,300,000
Finance lease obligations 11 12
Estimated fair value [Member]    
Financial assets    
Cash and due from banks 33,543 39,182
Interest-earning deposits with banks 141,241 135,028
Federal funds sold and securities borrowed or purchased under resale agreements 215,599 193,929
Held-to-maturity debt securities 171,298 175,797
Loans held for sale 3,755 2,681
Loans, net 961,749 931,928
Equity securities (cost method) 5,061 4,415
Total financial assets 1,532,246 1,482,960
Financial liabilities    
Deposits 189,026 166,107
Federal funds purchased and securities loaned or sold under repurchase agreements 234,371 232,687
Short-term borrowings 32,286 18,331
Long-term debt 178,318 173,953
Total financial liabilities 634,001 591,078
Fair Value Disclosures, Textual [Abstract]    
Loan commitments and standby, commercial and similar letters of credit 613 639
Estimated fair value [Member] | Fair Value, Inputs, Level 1 [Member]    
Financial assets    
Cash and due from banks 33,543 39,182
Interest-earning deposits with banks 140,909 134,695
Federal funds sold and securities borrowed or purchased under resale agreements 0 0
Held-to-maturity debt securities 2,032 2,051
Loans held for sale 0 0
Loans, net 0 0
Equity securities (cost method) 0 0
Total financial assets 176,484 175,928
Financial liabilities    
Deposits 0 0
Federal funds purchased and securities loaned or sold under repurchase agreements 0 0
Short-term borrowings 0 0
Long-term debt 0 0
Total financial liabilities 0 0
Estimated fair value [Member] | Fair value, inputs, level 2 [Member]    
Financial assets    
Cash and due from banks 0 0
Interest-earning deposits with banks 332 333
Federal funds sold and securities borrowed or purchased under resale agreements 215,599 193,929
Held-to-maturity debt securities 165,988 170,490
Loans held for sale 3,565 2,418
Loans, net 874 820
Equity securities (cost method) 0 0
Total financial assets 386,358 367,990
Financial liabilities    
Deposits 100,924 75,728
Federal funds purchased and securities loaned or sold under repurchase agreements 234,371 232,687
Short-term borrowings 32,286 18,331
Long-term debt 176,898 172,563
Total financial liabilities 544,479 499,309
Estimated fair value [Member] | Fair value, inputs, level 3 [Member]    
Financial assets    
Cash and due from banks 0 0
Interest-earning deposits with banks 0 0
Federal funds sold and securities borrowed or purchased under resale agreements 0 0
Held-to-maturity debt securities 3,278 3,256
Loans held for sale 190 263
Loans, net 960,875 931,108
Equity securities (cost method) 5,061 4,415
Total financial assets 969,404 939,042
Financial liabilities    
Deposits 88,102 90,379
Federal funds purchased and securities loaned or sold under repurchase agreements 0 0
Short-term borrowings 0 0
Long-term debt 1,420 1,390
Total financial liabilities $ 89,522 $ 91,769