Fair Value Measurement - Level 3 Inputs (Details) $ in Millions	Dec. 31, 2020 USD ($) $ / shares $ / MT $ / MWh	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans	$ 44,474	$ 44,955
MSRs	$ 3,276	4,699	$ 6,130	$ 6,030
Assumed par value for price input (in dollars per share) | $ / shares	$ 100
Recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans	$ 44,474	44,955
MSRs	3,276	4,699
Long-term debt, short-term borrowings, and deposits	437,627	233,844
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans	2,305	516
MSRs	3,276	4,699
Long-term debt, short-term borrowings, and deposits	41,510	$ 37,673
Other level 3 assets and liabilities, net	250
Discounted cash flows | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
MSRs	3,276
Other assets	299
Long-term debt, short-term borrowings, and deposits	818
Discounted cash flows | Recurring | Level 3 | Residential mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans	1,282
Discounted cash flows | Recurring | Level 3 | Nontrading loans | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans	805
Discounted cash flows | Recurring | Level 3 | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	20
Discounted cash flows | Recurring | Level 3 | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	(260)
Discounted cash flows | Recurring | Level 3 | Net foreign exchange derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	(136)
Discounted cash flows | Recurring | Level 3 | Mortgage-backed securities, U.S. GSEs and government agencies | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans	449
Discounted cash flows | Recurring | Level 3 | Residential mortgage-backed securities | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans	28
Market comparables | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Other assets	585
Market comparables | Recurring | Level 3 | Commercial mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans	466
Market comparables | Recurring | Level 3 | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities, trading	507
Market comparables | Recurring | Level 3 | Loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans	1,930
Market comparables | Recurring | Level 3 | Trading loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans	850
Market comparables | Recurring | Level 3 | Trading loans | Commercial
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans	43
Market comparables | Recurring | Level 3 | Nontrading loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans	1,100
Market comparables | Recurring | Level 3 | Nontrading loans | Commercial
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans	420
Market comparables | Recurring | Level 3 | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities, trading	28
Market comparables | Recurring | Level 3 | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	36
Market comparables | Recurring | Level 3 | Commercial | Commercial
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans	3
Option pricing | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Long-term debt, short-term borrowings, and deposits	27,912
Option pricing | Recurring | Level 3 | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	238
Option pricing | Recurring | Level 3 | Net foreign exchange derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	(298)
Option pricing | Recurring | Level 3 | Net equity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	(3,862)
Option pricing | Recurring | Level 3 | Net commodity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ (731)
Yield | Discounted cash flows | Level 3 | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Other assets, measurement inputs	0.04
Yield | Discounted cash flows | Level 3 | Minimum | Residential mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans, measurement input	0
Yield | Discounted cash flows | Level 3 | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Other assets, measurement inputs	0.30
Yield | Discounted cash flows | Level 3 | Maximum | Residential mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans, measurement input	0.18
Yield | Discounted cash flows | Level 3 | Average
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Other assets, measurement inputs	0.07
Yield | Discounted cash flows | Level 3 | Average | Residential mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans, measurement input	0.06
Prepayment speed | Discounted cash flows | Level 3 | Minimum | Residential mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans, measurement input	0
Prepayment speed | Discounted cash flows | Level 3 | Minimum | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0
Prepayment speed | Discounted cash flows | Level 3 | Minimum | Net foreign exchange derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.09
Prepayment speed | Discounted cash flows | Level 3 | Maximum | Residential mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans, measurement input	0.46
Prepayment speed | Discounted cash flows | Level 3 | Maximum | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.30
Prepayment speed | Discounted cash flows | Level 3 | Maximum | Net foreign exchange derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.09
Prepayment speed | Discounted cash flows | Level 3 | Average | Residential mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans, measurement input	0.10
Prepayment speed | Discounted cash flows | Level 3 | Average | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.08
Prepayment speed | Discounted cash flows | Level 3 | Average | Net foreign exchange derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.09
Conditional default rate | Discounted cash flows | Level 3 | Minimum | Residential mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans, measurement input	0
Conditional default rate | Discounted cash flows | Level 3 | Minimum | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.02
Conditional default rate | Discounted cash flows | Level 3 | Maximum | Residential mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans, measurement input	0.30
Conditional default rate | Discounted cash flows | Level 3 | Maximum | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	1
Conditional default rate | Discounted cash flows | Level 3 | Average | Residential mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans, measurement input	0.14
Conditional default rate | Discounted cash flows | Level 3 | Average | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.58
Loss severity | Discounted cash flows | Level 3 | Minimum | Residential mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans, measurement input	0
Loss severity | Discounted cash flows | Level 3 | Minimum | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	1
Loss severity | Discounted cash flows | Level 3 | Maximum | Residential mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans, measurement input	1.07
Loss severity | Discounted cash flows | Level 3 | Maximum | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	1
Loss severity | Discounted cash flows | Level 3 | Average | Residential mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans, measurement input	0.07
Loss severity | Discounted cash flows | Level 3 | Average | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	1
Price | Market comparables | Level 3 | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Other assets, measurement inputs | $ / shares	29
Price | Market comparables | Level 3 | Minimum | Commercial mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans, measurement input | $ / shares	0
Price | Market comparables | Level 3 | Minimum | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities, trading, measurement input | $ / shares	2
Price | Market comparables | Level 3 | Minimum | Loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans, measurement input | $ / shares	10
Price | Market comparables | Level 3 | Minimum | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities, trading, measurement input | $ / shares	1
Price | Market comparables | Level 3 | Minimum | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	1
Price | Market comparables | Level 3 | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Other assets, measurement inputs | $ / shares	29
Price | Market comparables | Level 3 | Maximum | Commercial mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans, measurement input | $ / shares	101
Price | Market comparables | Level 3 | Maximum | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities, trading, measurement input | $ / shares	116
Price | Market comparables | Level 3 | Maximum | Loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans, measurement input | $ / shares	104
Price | Market comparables | Level 3 | Maximum | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities, trading, measurement input | $ / shares	97
Price | Market comparables | Level 3 | Maximum | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	115
Price | Market comparables | Level 3 | Average
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Other assets, measurement inputs | $ / shares	29
Price | Market comparables | Level 3 | Average | Commercial mortgage-backed securities and loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities and loans, measurement input | $ / shares	84
Price | Market comparables | Level 3 | Average | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities, trading, measurement input | $ / shares	85
Price | Market comparables | Level 3 | Average | Loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans, measurement input | $ / shares	72
Price | Market comparables | Level 3 | Average | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt securities, trading, measurement input | $ / shares	57
Price | Market comparables | Level 3 | Average | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	71
Interest rate volatility | Option pricing | Level 3 | 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	0.0007
Interest rate volatility | Option pricing | Level 3 | Minimum | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.0007
Interest rate volatility | Option pricing | Level 3 | 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	0.0513
Interest rate volatility | Option pricing | Level 3 | Maximum | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.0513
Interest rate volatility | Option pricing | Level 3 | 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	0.0101
Interest rate volatility | Option pricing | Level 3 | Average | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.0101
Interest rate spread volatility | Option pricing | Level 3 | Minimum | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.0011
Interest rate spread volatility | Option pricing | Level 3 | Maximum | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.0023
Interest rate spread volatility | Option pricing | Level 3 | Average | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.0015
Interest rate correlation | Option pricing | Level 3 | 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	(0.65)
Interest rate correlation | Option pricing | Level 3 | Minimum | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	(0.65)
Interest rate correlation | Option pricing | Level 3 | 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	0.99
Interest rate correlation | Option pricing | Level 3 | Maximum | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.99
Interest rate correlation | Option pricing | Level 3 | 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
Interest rate correlation | Option pricing | Level 3 | Average | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.35
IR-FX correlation | Option pricing | Level 3 | 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)
IR-FX correlation | Option pricing | Level 3 | Minimum | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	(0.35)
IR-FX correlation | Option pricing | Level 3 | Minimum | Net foreign exchange derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	(0.40)
IR-FX correlation | Option pricing | Level 3 | 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	0.50
IR-FX correlation | Option pricing | Level 3 | Maximum | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.50
IR-FX correlation | Option pricing | Level 3 | Maximum | Net foreign exchange derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.65
IR-FX correlation | Option pricing | Level 3 | 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
IR-FX correlation | Option pricing | Level 3 | Average | Net interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0
IR-FX correlation | Option pricing | Level 3 | Average | Net foreign exchange derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.18
Credit correlation | Discounted cash flows | Level 3 | 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	0.34
Credit correlation | Discounted cash flows | Level 3 | Minimum | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.34
Credit correlation | Discounted cash flows | Level 3 | 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
Credit correlation | Discounted cash flows | Level 3 | Maximum | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.65
Credit correlation | Discounted cash flows | Level 3 | 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	0.48
Credit correlation | Discounted cash flows | Level 3 | Average | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.48
Credit spread | Discounted cash flows | Level 3 | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Other assets, measurement inputs	0.0045
Credit spread | Discounted cash flows | Level 3 | Minimum | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.0003
Credit spread | Discounted cash flows | Level 3 | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Other assets, measurement inputs	0.0045
Credit spread | Discounted cash flows | Level 3 | Maximum | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.1302
Credit spread | Discounted cash flows | Level 3 | Average
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Other assets, measurement inputs	0.0045
Credit spread | Discounted cash flows | Level 3 | Average | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.0441
Recovery rate | Discounted cash flows | Level 3 | Minimum | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0
Recovery rate | Discounted cash flows | Level 3 | Maximum | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.67
Recovery rate | Discounted cash flows | Level 3 | Average | Net credit derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.46
Forward equity price | Option pricing | Level 3 | Minimum | Net equity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.61
Forward equity price | Option pricing | Level 3 | Maximum | Net equity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	1.06
Forward equity price | Option pricing | Level 3 | Average | Net equity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.99
Equity volatility | Option pricing | Level 3 | Minimum | Net equity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.05
Equity volatility | Option pricing | Level 3 | Maximum | Net equity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	1.38
Equity volatility | Option pricing | Level 3 | Average | Net equity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.35
Equity correlation | Option pricing | Level 3 | 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	0.18
Equity correlation | Option pricing | Level 3 | Minimum | Net equity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.18
Equity correlation | Option pricing | Level 3 | 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	0.99
Equity correlation | Option pricing | Level 3 | Maximum | Net equity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.99
Equity correlation | Option pricing | Level 3 | 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	0.60
Equity correlation | Option pricing | Level 3 | Average | Net equity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.60
Equity-FX correlation | Option pricing | Level 3 | 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	(0.79)
Equity-FX correlation | Option pricing | Level 3 | Minimum | Net equity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	(0.79)
Equity-FX correlation | Option pricing | Level 3 | 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	0.55
Equity-FX correlation | Option pricing | Level 3 | Maximum | Net equity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.55
Equity-FX correlation | Option pricing | Level 3 | 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)
Equity-FX correlation | Option pricing | Level 3 | Average | Net equity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	(0.27)
Equity-IR correlation | Option pricing | Level 3 | 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
Equity-IR correlation | Option pricing | Level 3 | Minimum | Net equity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.20
Equity-IR correlation | Option pricing | Level 3 | 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	0.50
Equity-IR correlation | Option pricing | Level 3 | Maximum | Net equity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.50
Equity-IR correlation | Option pricing | Level 3 | 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	0.28
Equity-IR correlation | Option pricing | Level 3 | Average | Net equity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.28
Oil Commodity Forward | Option pricing | Level 3 | Minimum | Net commodity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs | $ / MT	600
Oil Commodity Forward | Option pricing | Level 3 | Maximum | Net commodity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs | $ / MT	609
Oil Commodity Forward | Option pricing | Level 3 | Average | Net commodity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs | $ / MT	605
Forward power price | Option pricing | Level 3 | Minimum | Net commodity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs | $ / MWh	12
Forward power price | Option pricing | Level 3 | Maximum | Net commodity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs | $ / MWh	55
Forward power price | Option pricing | Level 3 | Average | Net commodity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs | $ / MWh	34
Commodity volatility | Option pricing | Level 3 | Minimum | Net commodity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.01
Commodity volatility | Option pricing | Level 3 | Maximum | Net commodity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.58
Commodity volatility | Option pricing | Level 3 | Average | Net commodity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.29
Commodity correlation | Option pricing | Level 3 | Minimum | Net commodity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	(0.49)
Commodity correlation | Option pricing | Level 3 | Maximum | Net commodity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.95
Commodity correlation | Option pricing | Level 3 | Average | Net commodity derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability), measurement inputs	0.23