v3.26.1
Fair Value Measurement - Level 3 Inputs (Details)
$ in Millions
Jun. 30, 2026
USD ($)
$ / shares
$ / bbl
$ / MMBTU
Mar. 31, 2026
USD ($)
Dec. 31, 2025
USD ($)
Jun. 30, 2025
USD ($)
Mar. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Loans $ 62,889   $ 70,684      
MSRs 9,156 $ 9,093 9,167 $ 8,996 $ 9,127 $ 9,121
Equity securities for which quoted prices are not readily available $ 8,191   4,900 $ 4,121    
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 0.10          
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 0.0022          
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 0.0520          
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 0.0096          
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 0.43          
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 0.17          
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 0.57          
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 (0.45)          
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 0.06          
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 0.29          
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 0.78          
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 0.54          
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 0.0168          
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 0.0070          
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 0.60          
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 0.43          
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 1.82          
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 0.35          
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 0.15          
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 0.57          
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 (0.84)          
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 (0.33)          
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 0.20          
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 0.13          
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 0.40          
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 0.07          
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 0.14          
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 0.10          
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 0.03          
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          
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 93          
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 80          
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 177          
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 107          
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 112          
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 81          
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 107          
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 97          
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 0.21          
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 0.08          
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 0.0022          
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 0.0520          
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 0.0096          
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 0.0044          
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 0.0059          
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 0.0049          
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 0.43          
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 0.17          
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 0.57          
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 (0.45)          
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 0.06          
Level 3 | Net interest rate derivatives | Inflation volatility | Option pricing | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.0011          
Level 3 | Net interest rate derivatives | Inflation volatility | Option pricing | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.0174          
Level 3 | Net interest rate derivatives | Inflation volatility | Option pricing | Average            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Net derivative asset (liability), measurement inputs 0.0068          
Level 3 | Net interest rate 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 interest rate 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 0.15          
Level 3 | Net interest rate 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 0.05          
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 76          
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 0.55          
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 0.6942          
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 0.0390          
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 0.58          
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 0.15          
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 0.03          
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 0.15          
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 0.08          
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 0.83          
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 1.34          
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 0.02          
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 1.82          
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 0.37          
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          
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 0.49          
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 (0.82)          
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 0.71          
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 (0.15)          
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 0.10          
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 0.04          
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 44          
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 305          
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 148          
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 1          
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 6          
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 3          
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 0.39          
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 0.09          
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 (0.30)          
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 0.08          
Recurring            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Loans $ 62,889   70,684      
MSRs 9,156   9,167      
Long-term debt, short-term borrowings, and deposits 1,074,506   770,827      
Recurring | Level 3            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Loans 2,908   3,062      
MSRs 9,156   9,167      
Long-term debt, short-term borrowings, and deposits 76,139   $ 66,954      
Other level 3 asset and liabilities, net 1,626          
Equity securities for which quoted prices are not readily available 996          
Recurring | Level 3 | Discounted cash flows            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
MSRs 9,156          
Long-term debt, short-term borrowings, and deposits 1,834          
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 59,714          
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 823          
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 1,130          
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 617          
Recurring | Level 3 | Loans | Market comparables            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Loans 2,373          
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 797          
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) (44)          
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) 3,540          
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) (2,189)          
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) 19          
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) (46)          
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) 437          
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) (2,862)          
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) (3)          
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 238          
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 | Trading loans | Market comparables            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Loans 1,100          
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 93          
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 580          
Recurring | Level 3 | Non-trading loans | Market comparables            
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]            
Loans 1,300          
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 1,000          
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 $ 821