v3.25.2
Fair Value Measurement - Level 3 Inputs (Details)
$ in Millions
Jun. 30, 2025
USD ($)
$ / shares
$ / bbl
$ / MMBTU
Mar. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Jun. 30, 2024
USD ($)
Mar. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Loans $ 53,300   $ 41,350      
MSRs 8,996 $ 9,127 9,121 $ 8,847 $ 8,605 $ 8,522
Equity securities for which quoted prices are not readily available $ 4,121   3,700 $ 3,564    
Assumed par value for price input (in dollars per share) | $ / shares $ 100          
Level 3 | Yield | Discounted cash flows | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.05          
Level 3 | Yield | Discounted cash flows | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.20          
Level 3 | Yield | Discounted cash flows | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.11          
Level 3 | Loss severity | Discounted cash flows | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0          
Level 3 | Loss severity | Discounted cash flows | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 1          
Level 3 | Loss severity | Discounted cash flows | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.50          
Level 3 | Interest rate volatility | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.0025          
Level 3 | Interest rate volatility | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.0695          
Level 3 | Interest rate volatility | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.0109          
Level 3 | Bermudan switch value | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0          
Level 3 | Bermudan switch value | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.45          
Level 3 | Bermudan switch value | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.16          
Level 3 | Interest rate correlation | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs (0.64)          
Level 3 | Interest rate correlation | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.97          
Level 3 | Interest rate correlation | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.63          
Level 3 | IR-FX correlation | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs (0.35)          
Level 3 | IR-FX correlation | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.60          
Level 3 | IR-FX correlation | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.08          
Level 3 | Credit correlation | Discounted cash flows | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.26          
Level 3 | Credit correlation | Discounted cash flows | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.73          
Level 3 | Credit correlation | Discounted cash flows | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.47          
Level 3 | Credit spread | Discounted cash flows | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.0001          
Level 3 | Credit spread | Discounted cash flows | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.0273          
Level 3 | Credit spread | Discounted cash flows | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.0077          
Level 3 | Recovery rate | Discounted cash flows | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.20          
Level 3 | Recovery rate | Discounted cash flows | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.40          
Level 3 | Recovery rate | Discounted cash flows | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.37          
Level 3 | Equity volatility | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.02          
Level 3 | Equity volatility | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 1.11          
Level 3 | Equity volatility | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.27          
Level 3 | Equity correlation | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.05          
Level 3 | Equity correlation | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 1          
Level 3 | Equity correlation | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.55          
Level 3 | Equity-FX correlation | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs (0.80)          
Level 3 | Equity-FX correlation | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.65          
Level 3 | Equity-FX correlation | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs (0.32)          
Level 3 | Equity-IR correlation | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.05          
Level 3 | Equity-IR correlation | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.25          
Level 3 | Equity-IR correlation | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits, measurement inputs 0.12          
Level 3 | Residential mortgage-backed securities and loans | Yield | Discounted cash flows | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans, measurement input 0          
Level 3 | Residential mortgage-backed securities and loans | Yield | Discounted cash flows | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans, measurement input 0.93          
Level 3 | Residential mortgage-backed securities and loans | Yield | Discounted cash flows | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans, measurement input 0.07          
Level 3 | Residential mortgage-backed securities and loans | Prepayment speed | Discounted cash flows | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans, measurement input 0.02          
Level 3 | Residential mortgage-backed securities and loans | Prepayment speed | Discounted cash flows | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans, measurement input 0.13          
Level 3 | Residential mortgage-backed securities and loans | Prepayment speed | Discounted cash flows | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans, measurement input 0.09          
Level 3 | Residential mortgage-backed securities and loans | Conditional default rate | Discounted cash flows | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans, measurement input 0          
Level 3 | Residential mortgage-backed securities and loans | Conditional default rate | Discounted cash flows | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans, measurement input 0.07          
Level 3 | Residential mortgage-backed securities and loans | Conditional default rate | Discounted cash flows | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans, measurement input 0          
Level 3 | Residential mortgage-backed securities and loans | Loss severity | Discounted cash flows | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans, measurement input 0          
Level 3 | Residential mortgage-backed securities and loans | Loss severity | Discounted cash flows | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans, measurement input 1.10          
Level 3 | Residential mortgage-backed securities and loans | Loss severity | Discounted cash flows | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans, measurement input 0.05          
Level 3 | Commercial mortgage-backed securities and loans | Price (in USD/share) | Market comparables | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans, measurement input | $ / shares 0          
Level 3 | Commercial mortgage-backed securities and loans | Price (in USD/share) | Market comparables | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans, measurement input | $ / shares 84          
Level 3 | Commercial mortgage-backed securities and loans | Price (in USD/share) | Market comparables | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans, measurement input | $ / shares 81          
Level 3 | Corporate debt securities | Price (in USD/share) | Market comparables | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities, trading, measurement input | $ / shares 0          
Level 3 | Corporate debt securities | Price (in USD/share) | Market comparables | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities, trading, measurement input | $ / shares 197          
Level 3 | Corporate debt securities | Price (in USD/share) | Market comparables | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities, trading, measurement input | $ / shares 100          
Level 3 | Loans | Price (in USD/share) | Market comparables | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Loans, measurement input | $ / shares 0          
Level 3 | Loans | Price (in USD/share) | Market comparables | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Loans, measurement input | $ / shares 101          
Level 3 | Loans | Price (in USD/share) | Market comparables | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Loans, measurement input | $ / shares 82          
Level 3 | Non-U.S. government debt | Price (in USD/share) | Market comparables | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities, trading, measurement input | $ / shares 2          
Level 3 | Non-U.S. government debt | Price (in USD/share) | Market comparables | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities, trading, measurement input | $ / shares 121          
Level 3 | Non-U.S. government debt | Price (in USD/share) | Market comparables | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities, trading, measurement input | $ / shares 99          
Level 3 | Net interest rate derivatives | Prepayment speed | Discounted cash flows | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0          
Level 3 | Net interest rate derivatives | Prepayment speed | Discounted cash flows | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.20          
Level 3 | Net interest rate derivatives | Prepayment speed | Discounted cash flows | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.05          
Level 3 | Net interest rate derivatives | Interest rate volatility | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.0025          
Level 3 | Net interest rate derivatives | Interest rate volatility | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.0695          
Level 3 | Net interest rate derivatives | Interest rate volatility | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.0109          
Level 3 | Net interest rate derivatives | Interest rate spread volatility | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.0037          
Level 3 | Net interest rate derivatives | Interest rate spread volatility | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.0077          
Level 3 | Net interest rate derivatives | Interest rate spread volatility | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.0064          
Level 3 | Net interest rate derivatives | Bermudan switch value | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0          
Level 3 | Net interest rate derivatives | Bermudan switch value | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.45          
Level 3 | Net interest rate derivatives | Bermudan switch value | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.16          
Level 3 | Net interest rate derivatives | Interest rate correlation | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs (0.64)          
Level 3 | Net interest rate derivatives | Interest rate correlation | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.97          
Level 3 | Net interest rate derivatives | Interest rate correlation | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.63          
Level 3 | Net interest rate derivatives | IR-FX correlation | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs (0.35)          
Level 3 | Net interest rate derivatives | IR-FX correlation | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.60          
Level 3 | Net interest rate derivatives | IR-FX correlation | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.08          
Level 3 | Credit derivatives | Price (in USD/share) | Market comparables | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs | $ / shares 0          
Level 3 | Credit derivatives | Price (in USD/share) | Market comparables | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs | $ / shares 115          
Level 3 | Credit derivatives | Price (in USD/share) | Market comparables | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs | $ / shares 75          
Level 3 | Credit derivatives | Credit correlation | Discounted cash flows | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.27          
Level 3 | Credit derivatives | Credit correlation | Discounted cash flows | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.79          
Level 3 | Credit derivatives | Credit correlation | Discounted cash flows | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.47          
Level 3 | Credit derivatives | Credit spread | Discounted cash flows | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0          
Level 3 | Credit derivatives | Credit spread | Discounted cash flows | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 1.1330          
Level 3 | Credit derivatives | Credit spread | Discounted cash flows | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.0547          
Level 3 | Credit derivatives | Recovery rate | Discounted cash flows | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.10          
Level 3 | Credit derivatives | Recovery rate | Discounted cash flows | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.90          
Level 3 | Credit derivatives | Recovery rate | Discounted cash flows | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.56          
Level 3 | Net foreign exchange derivatives | Prepayment speed | Discounted cash flows | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.11          
Level 3 | Net foreign exchange derivatives | Prepayment speed | Discounted cash flows | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.11          
Level 3 | Net foreign exchange derivatives | Prepayment speed | Discounted cash flows | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.11          
Level 3 | Net foreign exchange derivatives | IR-FX correlation | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs (0.40)          
Level 3 | Net foreign exchange derivatives | IR-FX correlation | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.60          
Level 3 | Net foreign exchange derivatives | IR-FX correlation | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.21          
Level 3 | Net foreign exchange derivatives | Interest rate curve | Discounted cash flows | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.02          
Level 3 | Net foreign exchange derivatives | Interest rate curve | Discounted cash flows | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.28          
Level 3 | Net foreign exchange derivatives | Interest rate curve | Discounted cash flows | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.12          
Level 3 | Net equity derivatives | Forward equity price | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.82          
Level 3 | Net equity derivatives | Forward equity price | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 1.44          
Level 3 | Net equity derivatives | Forward equity price | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 1.01          
Level 3 | Net equity derivatives | Equity volatility | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.04          
Level 3 | Net equity derivatives | Equity volatility | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 1.98          
Level 3 | Net equity derivatives | Equity volatility | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.33          
Level 3 | Net equity derivatives | Equity correlation | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.05          
Level 3 | Net equity derivatives | Equity correlation | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 1          
Level 3 | Net equity derivatives | Equity correlation | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.55          
Level 3 | Net equity derivatives | Equity-FX correlation | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs (0.80)          
Level 3 | Net equity derivatives | Equity-FX correlation | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.65          
Level 3 | Net equity derivatives | Equity-FX correlation | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs (0.32)          
Level 3 | Net equity derivatives | Equity-IR correlation | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.05          
Level 3 | Net equity derivatives | Equity-IR correlation | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.25          
Level 3 | Net equity derivatives | Equity-IR correlation | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.12          
Level 3 | Net commodity derivatives | Oil commodity forward (in USD/ BBL) | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs | $ / bbl 37          
Level 3 | Net commodity derivatives | Oil commodity forward (in USD/ BBL) | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs | $ / bbl 287          
Level 3 | Net commodity derivatives | Oil commodity forward (in USD/ BBL) | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs | $ / bbl 153          
Level 3 | Net commodity derivatives | Natural gas commodity forward (in USD/ MMBTU) | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs | $ / MMBTU 2          
Level 3 | Net commodity derivatives | Natural gas commodity forward (in USD/ MMBTU) | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs | $ / MMBTU 7          
Level 3 | Net commodity derivatives | Natural gas commodity forward (in USD/ MMBTU) | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs | $ / MMBTU 4          
Level 3 | Net commodity derivatives | Commodity volatility | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.02          
Level 3 | Net commodity derivatives | Commodity volatility | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.47          
Level 3 | Net commodity derivatives | Commodity volatility | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.06          
Level 3 | Net commodity derivatives | Commodity correlation | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs (0.15)          
Level 3 | Net commodity derivatives | Commodity correlation | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.98          
Level 3 | Net commodity derivatives | Commodity correlation | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.10          
Recurring            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Loans $ 53,300   41,350      
MSRs 8,996   9,121      
Long-term debt, short-term borrowings, and deposits 952,212   586,175      
Recurring | Level 3            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Loans 2,252   2,416      
MSRs 8,996   9,121      
Long-term debt, short-term borrowings, and deposits 60,542   $ 51,780      
Other level 3 asset and liabilities, net 1,741          
Equity securities for which quoted prices are not readily available 803          
Recurring | Level 3 | Discounted cash flows            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
MSRs 8,996          
Long-term debt, short-term borrowings, and deposits 1,010          
Recurring | Level 3 | Option pricing            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Long-term debt, short-term borrowings, and deposits 46,889          
Recurring | Level 3 | Residential mortgage-backed securities and loans | Discounted cash flows            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans 843          
Recurring | Level 3 | Commercial mortgage-backed securities and loans | Market comparables            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans 1,299          
Recurring | Level 3 | Corporate debt securities | Market comparables            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities, trading 477          
Recurring | Level 3 | Loans | Market comparables            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Loans 1,362          
Recurring | Level 3 | Trading loans | Market comparables            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Loans 803          
Recurring | Level 3 | Trading loans | Market comparables | Commercial mortgage-backed securities            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans 65          
Recurring | Level 3 | Non-trading loans | Discounted cash flows | Residential mortgage-backed securities            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans 473          
Recurring | Level 3 | Non-trading loans | Market comparables            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Loans 559          
Recurring | Level 3 | Non-trading loans | Market comparables | Commercial mortgage-backed securities            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans 1,200          
Recurring | Level 3 | Non-U.S. government debt | Market comparables            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities, trading 205          
Recurring | Level 3 | Net interest rate derivatives | Discounted cash flows            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability) 9          
Recurring | Level 3 | Net interest rate derivatives | Option pricing            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability) 1,422          
Recurring | Level 3 | Credit derivatives | Discounted cash flows            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability) (837)          
Recurring | Level 3 | Credit derivatives | Market comparables            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability) 29          
Recurring | Level 3 | Net foreign exchange derivatives | Discounted cash flows            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability) (50)          
Recurring | Level 3 | Net foreign exchange derivatives | Option pricing            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability) 390          
Recurring | Level 3 | Net equity derivatives | Option pricing            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability) (3,204)          
Recurring | Level 3 | Net commodity derivatives | Option pricing            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability) 169          
Recurring | Level 3 | Mortgage-backed securities, U.S. GSEs and government agencies | Discounted cash flows | Residential mortgage-backed securities            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans 365          
Recurring | Level 3 | Residential mortgage-backed securities | Discounted cash flows | Residential mortgage-backed securities            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans 5          
Recurring | Level 3 | Commercial mortgage-backed securities | Market comparables | Commercial mortgage-backed securities            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Debt securities and loans 14          
Recurring | Level 3 | Other assets            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Equity securities for which quoted prices are not readily available $ 606