Variable Interest Entities - Consolidated VIE Assets and Liabilities (Details 3) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Trading assets - debt and equity instruments	$ 401,470	$ 450,028
Loans	725,586	733,796
Other assets, at fair value	111,421	101,775
Total assets	2,439,494	2,359,141	2,290,146
Beneficial interest liability, at fair value	55,090	63,191
Total liabilities	2,230,255	2,155,072
Variable Interest Entity, Primary Beneficiary
Information on assets and liabilities related to VIEs that are consolidated by the Firm [Abstract]
Loans	72,300	82,700
Other assets, at fair value	2,200	2,100
Total assets	83,700	96,800
Beneficial interest liability, at fair value	55,100	63,200
Other liabilities	1,100	1,200
Total liabilities	56,200	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	33,100	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	9,400
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	17,000
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	6,700
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	9,200	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	49,200	51,900
Other assets, at fair value	1,000	800
Total assets	50,200	52,700
Beneficial interest liability, at fair value	28,600	30,100
Other liabilities	0	0
Total liabilities	28,600	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	18,700	25,400
Other assets, at fair value	100	100
Total assets	18,800	25,500
Beneficial interest liability, at fair value	15,000	17,200
Other liabilities	0	0
Total liabilities	15,000	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 vehicles
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	7,300	9,900
Beneficial interest liability, at fair value	7,000	11,000
Other liabilities	0	0
Total liabilities	7,000	11,000
Variable Interest Entity, Primary Beneficiary | Municipal bonds vehicles | 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	7,200	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	1,800	2,000
Other assets, at fair value	0	0
Total assets	2,900	3,400
Beneficial interest liability, at fair value	2,000	2,300
Other liabilities	1,000	1,100
Total liabilities	3,000	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	2,600	3,400
Other assets, at fair value	1,000	1,100
Total assets	4,500	5,300
Beneficial interest liability, at fair value	2,500	2,600
Other liabilities	100	100
Total liabilities	2,600	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	900	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	$ 2,600	$ 3,300