Derivative Instruments - Impact on Balance Sheet (Details 1a) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	$ 1,642,154	$ 1,884,499
Fair value related to derivative payables	1,613,528	1,837,256
Carrying value of derivative trading assets	85,010	92,477
Carrying value of derivative trading liabilities	74,767	74,977
Interest rate contract
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	1,266,535	1,441,521
Fair value related to derivative payables	1,224,524	1,399,817
Carrying value of derivative trading assets	41,520	46,369
Carrying value of derivative trading liabilities	24,235	28,010
Credit derivatives
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	126,258	169,650
Fair value related to derivative payables	125,349	165,121
Carrying value of derivative trading assets	6,258	6,684
Carrying value of derivative trading liabilities	6,996	5,610
Foreign exchange
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	141,615	168,163
Fair value related to derivative payables	153,385	166,008
Carrying value of derivative trading assets	13,056	17,890
Carrying value of derivative trading liabilities	15,534	17,435
Equity
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	49,371	47,736
Fair value related to derivative payables	49,786	46,366
Carrying value of derivative trading assets	8,995	6,793
Carrying value of derivative trading liabilities	12,909	9,655
Commodity
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	58,375	57,429
Fair value related to derivative payables	60,484	59,944
Carrying value of derivative trading assets	15,181	14,741
Carrying value of derivative trading liabilities	15,093	14,267
Not Designated as Hedging Instrument [Member]
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	1,631,412	1,868,677
Fair value related to derivative payables	1,608,463	1,833,301
Not Designated as Hedging Instrument [Member] | Interest rate contract
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	1,259,472	1,433,900
Fair value related to derivative payables	1,222,353	1,397,625
Not Designated as Hedging Instrument [Member] | Credit derivatives
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	126,258	169,650
Fair value related to derivative payables	125,349	165,121
Not Designated as Hedging Instrument [Member] | Foreign exchange
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	139,071	163,497
Fair value related to derivative payables	151,841	165,353
Not Designated as Hedging Instrument [Member] | Equity
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	49,371	47,736
Fair value related to derivative payables	49,786	46,366
Not Designated as Hedging Instrument [Member] | Commodity
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	57,240	53,894
Fair value related to derivative payables	59,134	58,836
Designated as Hedging Instrument [Member]
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	10,742	15,822
Fair value related to derivative payables	5,065	3,955
Designated as Hedging Instrument [Member] | Interest rate contract
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	7,063	7,621
Fair value related to derivative payables	2,171	2,192
Designated as Hedging Instrument [Member] | Credit derivatives
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	0	0
Fair value related to derivative payables	0	0
Designated as Hedging Instrument [Member] | Foreign exchange
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	2,544	4,666
Fair value related to derivative payables	1,544	655
Designated as Hedging Instrument [Member] | Foreign currency-denominated debt [Member]
Derivatives Excluded From Trading Assets and Trading Liabilities [Abstract]
Foreign currency-denominated debt	10	11
Designated as Hedging Instrument [Member] | Equity
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	0	0
Fair value related to derivative payables	0	0
Designated as Hedging Instrument [Member] | Commodity
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	1,135	3,535
Fair value related to derivative payables	$ 1,350	$ 1,108