v3.25.2
FAIR VALUE MEASUREMENT - Valuation Techniques and Inputs for Level 3 Fair Value Measurements (Details)
Jun. 30, 2025
USD ($)
year
decimal
Dec. 31, 2024
USD ($)
decimal
year
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities available-for-sale (AFS) $ 235,802,000,000 $ 226,876,000,000
Marketable equity securities 583,000,000 578,000,000
Derivative assets 58,586,000,000 60,599,000,000
Mortgage-backed securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities available-for-sale (AFS) 37,003,000,000 29,931,000,000
Model-based | Level 3    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Securities borrowed and purchased under agreements to resell   128,000,000
State and municipal, foreign government, corporate and other debt securities   489,000,000
Marketable equity securities   22,000,000
Non-marketable equities 56,000,000 50,000,000
Loans and leases   177,000,000
Mortgage servicing rights 86,000,000 84,000,000
Interest-bearing deposits   39,000,000
Securities loaned and sold under agreement to repurchase 955,000,000  
Short-term borrowings and long-term debt 21,466,000,000  
Securities loaned or sold under agreements to repurchase   390,000,000
Model-based | Level 3 | Interest rate contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 3,773,000,000 3,574,000,000
Model-based | Level 3 | Foreign exchange contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 1,172,000,000 1,247,000,000
Model-based | Level 3 | Equity contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 4,273,000,000 4,345,000,000
Model-based | Level 3 | Commodity and other contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 1,901,000,000 1,716,000,000
Model-based | Level 3 | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 1,003,000,000 869,000,000
Model-based | Level 3 | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities available-for-sale (AFS) 647,000,000  
Yield analysis | Level 3    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Mortgage-backed securities   230,000,000
Asset-backed securities   47,000,000
Securities loaned or sold under agreements to repurchase and other trading liabilities   20,883,000,000
Yield analysis | Level 3 | Mortgage-backed securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities available-for-sale (AFS) 278,000,000  
Price-based | Level 3    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Mortgage-backed securities   214,000,000
State and municipal, foreign government, corporate and other debt securities   560,000,000
Marketable equity securities   131,000,000
Asset-backed securities   132,000,000
Non-marketable equities 70,000,000 81,000,000
Loans and leases   82,000,000
Securities loaned or sold under agreements to repurchase and other trading liabilities   27,000,000
Other financial assets and liabilities (gross)   14,000,000
Price-based | Level 3 | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 586,000,000  
Price-based | Level 3 | Mortgage-backed securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities available-for-sale (AFS) 443,000,000  
Price-based | Level 3 | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities available-for-sale (AFS) 845,000,000  
Comparables analysis | Level 3    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Non-marketable equities 272,000,000 222,000,000
Cash flow | Level 3    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
State and municipal, foreign government, corporate and other debt securities   140,000,000
Non-marketable equities   50,000,000
Mortgage servicing rights $ 676,000,000 $ 671,000,000
Minimum | Model-based | Level 3 | Yield    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
State and municipal, foreign government, corporate and other debt securities   0.0420
Mortgage servicing rights (0.0020) 0.0030
Minimum | Model-based | Level 3 | Yield | Interest rate contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0073 0.0169
Minimum | Model-based | Level 3 | Yield | Foreign exchange contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0073 0.0169
Minimum | Model-based | Level 3 | Yield | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.0230  
Minimum | Model-based | Level 3 | Credit spread    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
State and municipal, foreign government, corporate and other debt securities   0.0035
Securities borrowed and purchased under agreements to resell   0.10%
Minimum | Model-based | Level 3 | Credit spread | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.000566 0.000500
Minimum | Model-based | Level 3 | Credit spread | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.016700  
Minimum | Model-based | Level 3 | Equity volatility    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Loans and leases   0.3542
Short-term borrowings and long-term debt 0.0266  
Minimum | Model-based | Level 3 | Equity volatility | Interest rate contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0174  
Minimum | Model-based | Level 3 | Equity volatility | Equity contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0266 0
Minimum | Model-based | Level 3 | Equity volatility | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.0266  
Minimum | Model-based | Level 3 | IR normal volatility    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Securities loaned and sold under agreement to repurchase 0.0093  
Short-term borrowings and long-term debt 0.0004 (0.3400)
Securities loaned and sold under agreements to repurchase   0.0067
Minimum | Model-based | Level 3 | IR normal volatility | Interest rate contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0004 0.0016
Minimum | Model-based | Level 3 | IR normal volatility | Foreign exchange contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0040 0.0067
Minimum | Model-based | Level 3 | IR normal volatility | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.0040  
Minimum | Model-based | Level 3 | Recovery rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0676  
Minimum | Model-based | Level 3 | Recovery rate | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets   0.2000
Minimum | Model-based | Level 3 | Recovery rate | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.2500  
Minimum | Model-based | Level 3 | Interest rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Securities loaned and sold under agreement to repurchase 0.0368  
Securities loaned and sold under agreements to repurchase   0.0425
Securities borrowed and purchased under agreements to resell   3.81%
Minimum | Model-based | Level 3 | Interest rate | Interest rate contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets   0.7178
Minimum | Model-based | Level 3 | WAL    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Marketable equity securities | year   2.40
Derivative assets | year 1.90  
Minimum | Model-based | Level 3 | Equity forward    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Short-term borrowings and long-term debt 0.7142  
Minimum | Model-based | Level 3 | Equity forward | Equity contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.7142 0.7178
Minimum | Model-based | Level 3 | Discount rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Non-marketable equities 0.1260  
Minimum | Model-based | Level 3 | IR basis | Foreign exchange contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets (0.0712) (0.0750)
Minimum | Model-based | Level 3 | Equity-Equity correlation    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Short-term borrowings and long-term debt (0.3519)  
Minimum | Model-based | Level 3 | Equity-Equity correlation | Equity contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets (0.3622) (0.3622)
Minimum | Model-based | Level 3 | FX volatility    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement   0
Minimum | Model-based | Level 3 | FX volatility | Foreign exchange contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0389 0.0333
Minimum | Model-based | Level 3 | Forward price    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Loans and leases   0.0184
Interest-bearing deposits   1.0000
Minimum | Model-based | Level 3 | Forward price | Commodity and other contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0176 0.0184
Minimum | Model-based | Level 3 | Equity-FX correlation | Equity contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets (0.7500) (0.9333)
Short-term borrowings and long-term debt (0.7500)  
Minimum | Model-based | Level 3 | Commodity volatility | Commodity and other contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0867 0.0714
Minimum | Model-based | Level 3 | Inflation volatility | Interest rate contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0020  
Minimum | Model-based | Level 3 | Credit spread volatility | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets   0.2985
Minimum | Model-based | Level 3 | Credit correlation | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.2000  
Minimum | Model-based | Level 3 | Measurement Input, Recovery [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Marketable equity securities   8,628,000,000
Minimum | Yield analysis | Level 3 | Yield    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Mortgage-backed securities   0.0524
Asset-backed securities   0.0585
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement   0.0004
Minimum | Yield analysis | Level 3 | Yield | Mortgage-backed securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.0504  
Minimum | Price-based | Level 3 | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets   $ 468,000,000
Minimum | Price-based | Level 3 | Price    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Mortgage-backed securities   0.01
State and municipal, foreign government, corporate and other debt securities   0
Marketable equity securities   0
Asset-backed securities   3.46
Non-marketable equities 2.90 0.54
Loans and leases   73.88
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement   0
Other financial assets and liabilities (gross)   $ 91.12
Minimum | Price-based | Level 3 | Price | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 54.04 43.71
Minimum | Price-based | Level 3 | Price | Mortgage-backed securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 1.06  
Minimum | Price-based | Level 3 | Price | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0  
Minimum | Price-based | Level 3 | Upfront points | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0504 (0.0625)
Minimum | Comparables analysis | Level 3 | Illiquidity discount    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Non-marketable equities 0.0770 0.0740
Minimum | Comparables analysis | Level 3 | Revenue multiple    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Non-marketable equities | decimal 3.60 4.50
Minimum | Comparables analysis | Level 3 | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Non-marketable equities | decimal 16.80 16.20
Minimum | Cash flow | Level 3 | WAL    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
State and municipal, foreign government, corporate and other debt securities | year   3.59
Mortgage servicing rights | year 3.42 3.59
Minimum | Cash flow | Level 3 | Discount rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Non-marketable equities   0.0975
Maximum | Model-based | Level 3 | Yield    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
State and municipal, foreign government, corporate and other debt securities   0.1060
Mortgage servicing rights 0.1200 0.1200
Maximum | Model-based | Level 3 | Yield | Interest rate contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.1332 0.4632
Maximum | Model-based | Level 3 | Yield | Foreign exchange contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.1332 0.4632
Maximum | Model-based | Level 3 | Yield | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.1040  
Maximum | Model-based | Level 3 | Credit spread    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
State and municipal, foreign government, corporate and other debt securities   0.0550
Securities borrowed and purchased under agreements to resell   0.10%
Maximum | Model-based | Level 3 | Credit spread | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.068817 0.074727
Maximum | Model-based | Level 3 | Credit spread | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.055000  
Maximum | Model-based | Level 3 | Equity volatility    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Loans and leases   0.4194
Short-term borrowings and long-term debt 1.1870  
Maximum | Model-based | Level 3 | Equity volatility | Interest rate contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 1.1870  
Maximum | Model-based | Level 3 | Equity volatility | Equity contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 1.2953 1.4541
Maximum | Model-based | Level 3 | Equity volatility | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 1.8016  
Maximum | Model-based | Level 3 | IR normal volatility    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Securities loaned and sold under agreement to repurchase 0.0109  
Short-term borrowings and long-term debt 0.0300 0.6000
Securities loaned and sold under agreements to repurchase   0.0113
Maximum | Model-based | Level 3 | IR normal volatility | Interest rate contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0300 0.2000
Maximum | Model-based | Level 3 | IR normal volatility | Foreign exchange contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0105 0.0113
Maximum | Model-based | Level 3 | IR normal volatility | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.0105  
Maximum | Model-based | Level 3 | Recovery rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0676  
Maximum | Model-based | Level 3 | Recovery rate | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets   0.7200
Maximum | Model-based | Level 3 | Recovery rate | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.2500  
Maximum | Model-based | Level 3 | Interest rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Securities loaned and sold under agreement to repurchase 0.0567  
Securities loaned and sold under agreements to repurchase   0.0485
Securities borrowed and purchased under agreements to resell   3.81%
Maximum | Model-based | Level 3 | Interest rate | Interest rate contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets   3.3429
Maximum | Model-based | Level 3 | WAL    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Marketable equity securities | year   2.40
Derivative assets | year 1.90  
Maximum | Model-based | Level 3 | Equity forward    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Short-term borrowings and long-term debt 3.4298  
Maximum | Model-based | Level 3 | Equity forward | Equity contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 3.4298 3.3429
Maximum | Model-based | Level 3 | Discount rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Non-marketable equities 0.1750  
Maximum | Model-based | Level 3 | IR basis | Foreign exchange contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.4450 0.6475
Maximum | Model-based | Level 3 | Equity-Equity correlation    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Short-term borrowings and long-term debt 0.5000  
Maximum | Model-based | Level 3 | Equity-Equity correlation | Equity contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.9851 0.9900
Maximum | Model-based | Level 3 | FX volatility    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement   1.4541
Maximum | Model-based | Level 3 | FX volatility | Foreign exchange contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.1676 0.2764
Maximum | Model-based | Level 3 | Forward price    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Loans and leases   2.4441
Interest-bearing deposits   1.0000
Maximum | Model-based | Level 3 | Forward price | Commodity and other contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 3.0357 2.4441
Maximum | Model-based | Level 3 | Equity-FX correlation | Equity contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.7000 0.7000
Short-term borrowings and long-term debt 0.7000  
Maximum | Model-based | Level 3 | Commodity volatility | Commodity and other contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 2.7808 2.8561
Maximum | Model-based | Level 3 | Inflation volatility | Interest rate contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0632  
Maximum | Model-based | Level 3 | Credit spread volatility | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets   0.8144
Maximum | Model-based | Level 3 | Credit correlation | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.9500  
Maximum | Model-based | Level 3 | Measurement Input, Recovery [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Marketable equity securities   8,628,000,000
Maximum | Yield analysis | Level 3 | Yield    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Mortgage-backed securities   0.1843
Asset-backed securities   0.1276
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement   0.2000
Maximum | Yield analysis | Level 3 | Yield | Mortgage-backed securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.2256  
Maximum | Price-based | Level 3 | Price    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Mortgage-backed securities   99.81
State and municipal, foreign government, corporate and other debt securities   173.20
Marketable equity securities   14,382.07
Asset-backed securities   132.54
Non-marketable equities 161.37 2,960.96
Loans and leases   99.25
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement   14,382.07
Other financial assets and liabilities (gross)   $ 104.49
Maximum | Price-based | Level 3 | Price | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 114.32 103.53
Maximum | Price-based | Level 3 | Price | Mortgage-backed securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 148.90  
Maximum | Price-based | Level 3 | Price | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 193.44  
Maximum | Price-based | Level 3 | Upfront points | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 1.0617 1.1052
Maximum | Comparables analysis | Level 3 | Illiquidity discount    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Non-marketable equities 0.3300 0.3300
Maximum | Comparables analysis | Level 3 | Revenue multiple    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Non-marketable equities | decimal 33.56 16.31
Maximum | Comparables analysis | Level 3 | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Non-marketable equities | decimal 16.80 16.20
Maximum | Cash flow | Level 3 | WAL    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
State and municipal, foreign government, corporate and other debt securities | year   8.82
Mortgage servicing rights | year 8.62 8.82
Maximum | Cash flow | Level 3 | Discount rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Non-marketable equities   0.1750
Weighted Average | Model-based | Level 3 | Yield    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
State and municipal, foreign government, corporate and other debt securities   0.0988
Mortgage servicing rights 0.0654 0.0682
Weighted Average | Model-based | Level 3 | Yield | Interest rate contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0351 0.0564
Weighted Average | Model-based | Level 3 | Yield | Foreign exchange contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0527 0.0926
Weighted Average | Model-based | Level 3 | Yield | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.0954  
Weighted Average | Model-based | Level 3 | Credit spread    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
State and municipal, foreign government, corporate and other debt securities   0.0277
Securities borrowed and purchased under agreements to resell   0.10%
Weighted Average | Model-based | Level 3 | Credit spread | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.007111 0.010050
Weighted Average | Model-based | Level 3 | Credit spread | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.039634  
Weighted Average | Model-based | Level 3 | Equity volatility    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Loans and leases   0.3721
Short-term borrowings and long-term debt 0.1962  
Weighted Average | Model-based | Level 3 | Equity volatility | Interest rate contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.1685  
Weighted Average | Model-based | Level 3 | Equity volatility | Equity contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.3197 0.3289
Weighted Average | Model-based | Level 3 | Equity volatility | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.3912  
Weighted Average | Model-based | Level 3 | IR normal volatility    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Securities loaned and sold under agreement to repurchase 0.0106  
Short-term borrowings and long-term debt 0.0088 0.2729
Securities loaned and sold under agreements to repurchase   0.0093
Weighted Average | Model-based | Level 3 | IR normal volatility | Interest rate contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0081 0.0218
Weighted Average | Model-based | Level 3 | IR normal volatility | Foreign exchange contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0082 0.0093
Weighted Average | Model-based | Level 3 | IR normal volatility | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.0090  
Weighted Average | Model-based | Level 3 | Recovery rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0676  
Weighted Average | Model-based | Level 3 | Recovery rate | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets   0.4154
Weighted Average | Model-based | Level 3 | Recovery rate | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.2500  
Weighted Average | Model-based | Level 3 | Interest rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Securities loaned and sold under agreement to repurchase 0.0406  
Securities loaned and sold under agreements to repurchase   0.0428
Securities borrowed and purchased under agreements to resell   3.81%
Weighted Average | Model-based | Level 3 | Interest rate | Interest rate contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets   1.0648
Weighted Average | Model-based | Level 3 | WAL    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Marketable equity securities | year   2.40
Derivative assets | year 1.90  
Weighted Average | Model-based | Level 3 | Equity forward    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Short-term borrowings and long-term debt 1.0587  
Weighted Average | Model-based | Level 3 | Equity forward | Equity contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 1.0673 1.0590
Weighted Average | Model-based | Level 3 | Discount rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Non-marketable equities 0.1541  
Weighted Average | Model-based | Level 3 | IR basis | Foreign exchange contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0556 0.0501
Weighted Average | Model-based | Level 3 | Equity-Equity correlation    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Short-term borrowings and long-term debt 0.2592  
Weighted Average | Model-based | Level 3 | Equity-Equity correlation | Equity contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.6947 0.7243
Weighted Average | Model-based | Level 3 | FX volatility    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement   0.1981
Weighted Average | Model-based | Level 3 | FX volatility | Foreign exchange contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0938 0.1255
Weighted Average | Model-based | Level 3 | Forward price    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Loans and leases   1.0292
Interest-bearing deposits   1.0000
Weighted Average | Model-based | Level 3 | Forward price | Commodity and other contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 1.0193 1.1584
Weighted Average | Model-based | Level 3 | Equity-FX correlation | Equity contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets (0.0595) (0.1452)
Short-term borrowings and long-term debt (0.0974)  
Weighted Average | Model-based | Level 3 | Commodity volatility | Commodity and other contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.5019 0.3586
Weighted Average | Model-based | Level 3 | Inflation volatility | Interest rate contracts (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.0236  
Weighted Average | Model-based | Level 3 | Credit spread volatility | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets   0.6758
Weighted Average | Model-based | Level 3 | Credit correlation | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.4926  
Weighted Average | Model-based | Level 3 | Measurement Input, Recovery [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Marketable equity securities   8,628,000,000
Weighted Average | Yield analysis | Level 3 | Yield    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Mortgage-backed securities   0.0925
Asset-backed securities   0.0807
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement   0.0154
Weighted Average | Yield analysis | Level 3 | Yield | Mortgage-backed securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 0.0766  
Weighted Average | Price-based | Level 3 | Price    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Mortgage-backed securities   35.24
State and municipal, foreign government, corporate and other debt securities   98.52
Marketable equity securities   442.64
Asset-backed securities   74.86
Non-marketable equities 91.32 432.84
Loans and leases   85.09
Securities loaned or sold under agreements to repurchase and other trading liabilities, measurement   91.47
Other financial assets and liabilities (gross)   $ 100.04
Weighted Average | Price-based | Level 3 | Price | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 95.80 85.76
Weighted Average | Price-based | Level 3 | Price | Mortgage-backed securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 45.95  
Weighted Average | Price-based | Level 3 | Price | State And Municipal, Foreign Government, Corporate And Other Debt Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Debt securities, measurement input 98.65  
Weighted Average | Price-based | Level 3 | Upfront points | Credit derivatives (gross)    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Derivative assets 0.6033 0.4393
Weighted Average | Comparables analysis | Level 3 | Illiquidity discount    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Non-marketable equities 0.1636 0.1647
Weighted Average | Comparables analysis | Level 3 | Revenue multiple    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Non-marketable equities | decimal 14.49 11.97
Weighted Average | Comparables analysis | Level 3 | EBITDA multiples    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Non-marketable equities | decimal 16.80 16.20
Weighted Average | Cash flow | Level 3 | WAL    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
State and municipal, foreign government, corporate and other debt securities | year   7.57
Mortgage servicing rights | year 7.39 7.57
Weighted Average | Cash flow | Level 3 | Discount rate    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Non-marketable equities   0.1328