Fair Value Measurement - Level 3 Inputs (Details)		3 Months Ended
	Mar. 31, 2016 USD ($) $ / bbl	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ (2,791,000,000)	$ (2,791,000,000)	$ (1,749,000,000)	$ (1,848,000,000)	$ (2,061,000,000)
Recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liability fair value	212,849,000,000	212,849,000,000	191,103,000,000
Beneficial interests issued by consolidated VIEs	670,000,000	670,000,000	787,000,000
Level 3 Analysis - Supplemental Data:
Trading Securities	295,887,000,000	295,887,000,000	284,101,000,000
Trading liabilities	147,282,000,000	147,282,000,000	126,897,000,000
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liability fair value	26,412,000,000	26,412,000,000	25,528,000,000
Beneficial interests issued by consolidated VIEs	649,000,000	649,000,000	549,000,000
Level 3 Analysis - Supplemental Data:
Trading Securities	11,313,000,000	11,313,000,000	11,930,000,000
Trading liabilities	$ 10,167,000,000	10,167,000,000	9,758,000,000
Long-term debt, other borrowed funds, and deposits | Discounted cash flows | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Credit correlation	30.00%
Long-term debt, other borrowed funds, and deposits | Discounted cash flows | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Credit correlation	85.00%
Long-term debt, other borrowed funds, and deposits | Discounted cash flows | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liability fair value	$ 505,000,000	505,000,000
Long-term debt, other borrowed funds, and deposits | Option pricing | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Interest rate correlation	(30.00%)
Interest rate spread volatility	3.00%
Foreign exchange correlation	0.00%
Equity correlation	(50.00%)
Long-term debt, other borrowed funds, and deposits | Option pricing | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Interest rate correlation	96.00%
Interest rate spread volatility	38.00%
Foreign exchange correlation	70.00%
Equity correlation	80.00%
Long-term debt, other borrowed funds, and deposits | Option pricing | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liability fair value	$ 15,069,000,000	15,069,000,000
Beneficial interests issued by consolidated VIEs | Discounted cash flows | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Yield	3.00%
Prepayment speed	7.00%
Conditional default rate	2.00%
Loss severity	30.00%
Beneficial interests issued by consolidated VIEs | Discounted cash flows | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Yield	7.00%
Prepayment speed	8.00%
Conditional default rate	20.00%
Loss severity	30.00%
Beneficial interests issued by consolidated VIEs | Discounted cash flows | Weighted average
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Yield	4.00%
Prepayment speed	7.00%
Conditional default rate	3.00%
Loss severity	30.00%
Credit derivatives with underlying mortgage risk | Recurring | Level 3
Level 3 Analysis - Supplemental Data:
Trading liabilities	$ 283,000,000	283,000,000
Credit derivatives with underlying asset-backed securities risk | Recurring | Level 3
Level 3 Analysis - Supplemental Data:
Trading liabilities	361,000,000	361,000,000
Interest rate
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ 846,000,000	846,000,000	876,000,000	650,000,000	626,000,000
Interest rate | Option pricing | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Interest rate correlation	(30.00%)
Interest rate spread volatility	3.00%
Interest rate | Option pricing | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Interest rate correlation	96.00%
Interest rate spread volatility	38.00%
Interest rate | Option pricing | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ 846,000,000	846,000,000
Credit
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ 402,000,000	402,000,000	549,000,000	275,000,000	189,000,000
Credit | Discounted cash flows | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Credit correlation	30.00%
Credit | Discounted cash flows | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Credit correlation	85.00%
Credit | Discounted cash flows | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ 402,000,000	402,000,000
Foreign exchange
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ (1,032,000,000)	(1,032,000,000)	(725,000,000)	707,000,000	(526,000,000)
Foreign exchange | Option pricing | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Foreign exchange correlation	0.00%
Foreign exchange | Option pricing | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Foreign exchange correlation	70.00%
Foreign exchange | Option pricing | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ (1,032,000,000)	(1,032,000,000)
Equity
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ (2,055,000,000)	(2,055,000,000)	(1,514,000,000)	(2,745,000,000)	(1,785,000,000)
Equity | Option pricing | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity volatility	15.00%
Equity | Option pricing | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity volatility	70.00%
Equity | Option pricing | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ (2,055,000,000)	(2,055,000,000)
Commodity
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ (952,000,000)	(952,000,000)	$ (935,000,000)	$ (735,000,000)	$ (565,000,000)
Commodity | Discounted cash flows | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Forward commodity price | $ / bbl	23
Commodity | Discounted cash flows | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Forward commodity price | $ / bbl	45
Commodity | Discounted cash flows | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ (952,000,000)	(952,000,000)
Residential mortgage-backed securities and loans | Discounted cash flows | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Yield	3.00%
Prepayment speed	0.00%
Conditional default rate	0.00%
Loss severity	0.00%
Residential mortgage-backed securities and loans | Discounted cash flows | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Yield	17.00%
Prepayment speed	20.00%
Conditional default rate	20.00%
Loss severity	100.00%
Residential mortgage-backed securities and loans | Discounted cash flows | Weighted average
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Yield	5.00%
Prepayment speed	6.00%
Conditional default rate	3.00%
Loss severity	30.00%
Residential mortgage-backed securities and loans | Discounted cash flows | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset fair value	$ 4,630,000,000	4,630,000,000
Commercial mortgage-backed securities and loans | Discounted cash flows | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Yield	1.00%
Conditional default rate	0.00%
Loss severity	40.00%
Commercial mortgage-backed securities and loans | Discounted cash flows | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Yield	25.00%
Conditional default rate	100.00%
Commercial mortgage-backed securities and loans | Discounted cash flows | Weighted average
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Yield	6.00%
Conditional default rate	27.00%
Loss severity	40.00%
Commercial mortgage-backed securities and loans | Discounted cash flows | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset fair value	$ 2,557,000,000	$ 2,557,000,000
Corporate debt securities, obligations of U.S. states and municipalities, and other | Discounted cash flows | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Yield	2.00%
Credit spread		0.50%
Corporate debt securities, obligations of U.S. states and municipalities, and other | Discounted cash flows | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Yield	20.00%
Credit spread		2.25%
Corporate debt securities, obligations of U.S. states and municipalities, and other | Discounted cash flows | Weighted average
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Yield	6.00%
Credit spread		1.68%
Corporate debt securities, obligations of U.S. states and municipalities, and other | Discounted cash flows | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset fair value	$ 2,534,000,000	$ 2,534,000,000
Corporate debt securities, obligations of U.S. states and municipalities, and other | Market comparables | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price	0
Corporate debt securities, obligations of U.S. states and municipalities, and other | Market comparables | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price	238
Corporate debt securities, obligations of U.S. states and municipalities, and other | Market comparables | Weighted average
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price	91
Corporate debt securities, obligations of U.S. states and municipalities, and other | Market comparables | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset fair value	$ 3,233,000,000	$ 3,233,000,000
Collateralized loan obligations | Discounted cash flows | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Prepayment speed	20.00%
Conditional default rate	2.00%
Loss severity	40.00%
Credit spread		4.25%
Collateralized loan obligations | Discounted cash flows | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Prepayment speed	20.00%
Conditional default rate	2.00%
Loss severity	40.00%
Credit spread		7.05%
Collateralized loan obligations | Discounted cash flows | Weighted average
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Prepayment speed	20.00%
Conditional default rate	2.00%
Loss severity	40.00%
Credit spread		4.54%
Collateralized loan obligations | Discounted cash flows | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset fair value	$ 752,000,000	$ 752,000,000
Collateralized loan obligations | Market comparables | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price	0
Collateralized loan obligations | Market comparables | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price	100
Collateralized loan obligations | Market comparables | Weighted average
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price	57
Collateralized loan obligations | Market comparables | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset fair value	133,000,000	133,000,000
MSRs | Discounted cash flows | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset fair value	$ 5,658,000,000	5,658,000,000
Private equity investments | Market comparables | Private equity investments | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
EBITDA multiple	6.0
Liquidity adjustment	0.00%
Private equity investments | Market comparables | Private equity investments | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
EBITDA multiple	9.9
Liquidity adjustment	23.00%
Private equity investments | Market comparables | Private equity investments | Weighted average
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
EBITDA multiple	7.8
Liquidity adjustment	9.00%
Private equity investments | Market comparables | Recurring | Level 3 | Private equity investments
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset fair value	$ 1,644,000,000	1,644,000,000
Credit derivatives with underlying mortgage risk | Recurring | Level 3
Level 3 Analysis - Supplemental Data:
Trading Securities	320,000,000	320,000,000
Credit derivatives with underlying asset-backed securities risk | Recurring | Level 3
Level 3 Analysis - Supplemental Data:
Trading Securities	$ 397,000,000	$ 397,000,000