Variable Interest Entities - Consolidated VIE Assets and Liabilities (Details 3) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Trading assets - debt and equity instruments	$ 430,991	$ 450,028
Loans	728,886	733,796
Other assets, at fair value	102,101	101,775
Total assets	2,389,349	2,359,141	2,320,164
Beneficial interest liability, at fair value	58,300	63,191
Total liabilities	2,182,263	2,155,072
Variable Interest Entity, Primary Beneficiary
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Loans	73,700	82,700
Other assets, at fair value	1,900	2,100
Total assets	87,500	96,800
Beneficial interest liability, at fair value	58,300	63,200
Other liabilities	1,300	1,200
Total liabilities	59,600	64,400
Variable Interest Entity, Primary Beneficiary | Long Term Beneficial Interests
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Beneficial interest liability, at fair value	32,600	35,000
Variable Interest Entity, Primary Beneficiary | Long Term Beneficial Interests Maturities Under One Year
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Beneficial interest liability, at fair value	9,100
Variable Interest Entity, Primary Beneficiary | Long Term Beneficial Interests Maturities Between One And Five Years
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Beneficial interest liability, at fair value	16,600
Variable Interest Entity, Primary Beneficiary | Long Term Beneficial Interests Maturities Over Five Years
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Beneficial interest liability, at fair value	6,900
Variable Interest Entity, Primary Beneficiary | Debt and equity securities
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Trading assets - debt and equity instruments	11,900	12,000
Variable Interest Entity, Primary Beneficiary | Firm Sponsored Credit Card Securitization Trusts
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Loans	48,400	51,900
Other assets, at fair value	700	800
Total assets	49,100	52,700
Beneficial interest liability, at fair value	27,900	30,100
Other liabilities	0	0
Total liabilities	27,900	30,100
Variable Interest Entity, Primary Beneficiary | Firm Sponsored Credit Card Securitization Trusts | Debt and equity securities
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Trading assets - debt and equity instruments	0	0
Variable Interest Entity, Primary Beneficiary | Firm Administered Multi Seller Conduits
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Loans	20,200	25,400
Other assets, at fair value	100	100
Total assets	20,300	25,500
Beneficial interest liability, at fair value	16,500	17,200
Other liabilities	0	0
Total liabilities	16,500	17,200
Variable Interest Entity, Primary Beneficiary | Firm Administered Multi Seller Conduits | Debt and equity securities
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Trading assets - debt and equity instruments	0	0
Variable Interest Entity, Primary Beneficiary | Municipal Bonds
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Loans	0	0
Other assets, at fair value	100	100
Total assets	9,900	9,900
Beneficial interest liability, at fair value	9,200	11,000
Other liabilities	100	0
Total liabilities	9,300	11,000
Variable Interest Entity, Primary Beneficiary | Municipal Bonds | Debt and equity securities
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Trading assets - debt and equity instruments	9,800	9,800
Variable Interest Entity, Primary Beneficiary | V I E Program Type Three
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Loans	1,900	2,000
Other assets, at fair value	0	0
Total assets	3,000	3,400
Beneficial interest liability, at fair value	2,100	2,300
Other liabilities	1,000	1,100
Total liabilities	3,100	3,400
Variable Interest Entity, Primary Beneficiary | V I E Program Type Three | Debt and equity securities
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Trading assets - debt and equity instruments	1,100	1,400
Variable Interest Entity, Primary Beneficiary | Vie Program Type Other
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Loans	3,200	3,400
Other assets, at fair value	1,000	1,100
Total assets	5,200	5,300
Beneficial interest liability, at fair value	2,600	2,600
Other liabilities	200	100
Total liabilities	2,800	2,700
Variable Interest Entity, Primary Beneficiary | Vie Program Type Other | Debt and equity securities
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Trading assets - debt and equity instruments	1,000	800
Student Loans | Variable Interest Entity, Primary Beneficiary
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$ 3,200	$ 3,300