Fair Value Measurement - Level 3 Inputs (Details)		12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2015 USD ($) $ / bbl	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ (1,749,000,000)	$ (1,749,000,000)	$ (2,061,000,000)	$ 326,000,000	$ 1,893,000,000
Recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liability fair value	191,103,000,000	191,103,000,000	215,883,000,000
Beneficial interests issued by consolidated VIEs	787,000,000	787,000,000	2,162,000,000
Level 3 Analysis - Supplemental Data:
Trading securities	284,101,000,000	284,101,000,000	319,889,000,000
Trading liabilities	126,897,000,000	126,897,000,000	152,815,000,000
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liability fair value	25,528,000,000	25,528,000,000	32,059,000,000
Beneficial interests issued by consolidated VIEs	549,000,000	549,000,000	1,146,000,000
Level 3 Analysis - Supplemental Data:
Trading securities	11,930,000,000	11,930,000,000	22,489,000,000
Trading liabilities	9,758,000,000	9,758,000,000	14,698,000,000
Interest rate
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ 876,000,000	876,000,000	626,000,000	2,379,000,000	3,322,000,000
Interest rate | Option pricing | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Interest rate correlation	(52.00%)
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	99.00%
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)	$ 876,000,000	876,000,000
Credit
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ 549,000,000	549,000,000	189,000,000	95,000,000	1,873,000,000
Credit | Discounted cash flows | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Credit correlation	35.00%
Credit | Discounted cash flows | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Credit correlation	90.00%
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)	$ 549,000,000	549,000,000
Foreign exchange
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ (725,000,000)	(725,000,000)	(526,000,000)	(1,200,000,000)	(1,750,000,000)
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	60.00%
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)	$ (725,000,000)	(725,000,000)
Equity
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ (1,514,000,000)	(1,514,000,000)	(1,785,000,000)	(1,063,000,000)	(1,806,000,000)
Equity | Option pricing | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity volatility	20.00%
Equity | Option pricing | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity volatility	65.00%
Equity | Option pricing | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	$ (1,514,000,000)	(1,514,000,000)
Commodity
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net derivative asset (liability)	(935,000,000)	$ (935,000,000)	$ (565,000,000)	$ 115,000,000	$ 254,000,000
Commodity | Discounted cash flows | Minimum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Forward commodity price | $ / bbl		22
Commodity | Discounted cash flows | Maximum
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Forward commodity price | $ / bbl		46
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)	$ (935,000,000)	$ (935,000,000)
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	35.00%
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	90.00%
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	$ 495,000,000	495,000,000
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	(52.00%)
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	99.00%
Interest rate spread volatility	38.00%
Foreign exchange correlation	60.00%
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	$ 14,707,000,000	14,707,000,000
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	4.00%
Prepayment speed	1.00%
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	28.00%
Prepayment speed	12.00%
Conditional default rate	15.00%
Loss severity	100.00%
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	6.00%
Conditional default rate	2.00%
Loss severity	31.00%
Credit derivatives with underlying mortgage risk | Recurring | Level 3
Level 3 Analysis - Supplemental Data:
Trading liabilities	$ 310,000,000	310,000,000
Credit derivatives with underlying asset-backed securities risk | Recurring | Level 3
Level 3 Analysis - Supplemental Data:
Trading liabilities	$ 401,000,000	401,000,000
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	26.00%
Prepayment speed	20.00%
Conditional default rate	33.00%
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	6.00%
Prepayment speed	6.00%
Conditional default rate	2.00%
Loss severity	28.00%
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	$ 5,212,000,000	5,212,000,000
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	91.00%
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	29.00%
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	$ 2,844,000,000	$ 2,844,000,000
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	1.00%
Credit spread		0.60%
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	5.00%
Credit spread		1.46%
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	$ 3,277,000,000	$ 3,277,000,000
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	168
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	89
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	$ 2,740,000,000	$ 2,740,000,000
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		3.54%
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		5.50%
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		3.96%
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	$ 759,000,000	$ 759,000,000
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	99
Collateralized loan obligations | Market comparables | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price	69
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	180,000,000	180,000,000
Mortgage servicing rights | Discounted cash flows | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Asset fair value	$ 6,608,000,000	6,608,000,000
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	7.2
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	10.4
Liquidity adjustment	13.00%
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	8.5
Liquidity adjustment	8.00%
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	$ 1,657,000,000	1,657,000,000
Credit derivatives with underlying mortgage risk | Recurring | Level 3
Level 3 Analysis - Supplemental Data:
Trading securities	349,000,000	349,000,000
Credit derivatives with underlying asset-backed securities risk | Recurring | Level 3
Level 3 Analysis - Supplemental Data:
Trading securities	$ 434,000,000	$ 434,000,000