Derivative Instruments - Impact on Balance Sheet (Details 1a) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	$ 1,526,042	$ 1,672,377
Carrying value of derivative trading assets	70,609	74,983
Fair value related to derivative payables	1,505,807	1,649,555
Carrying value of derivative trading liabilities	61,989	70,656
Interest rate contract
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	1,173,789	1,329,248
Carrying value of derivative trading assets	34,280	39,205
Fair value related to derivative payables	1,134,696	1,287,614
Carrying value of derivative trading liabilities	18,611	24,906
Credit derivatives
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	103,399	100,310
Carrying value of derivative trading assets	3,664	1,735
Fair value related to derivative payables	101,350	100,027
Carrying value of derivative trading liabilities	3,134	2,504
Foreign exchange
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	141,491	148,259
Carrying value of derivative trading assets	12,346	14,142
Fair value related to derivative payables	156,414	161,642
Carrying value of derivative trading liabilities	14,806	18,601
Equity
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	46,438	42,662
Carrying value of derivative trading assets	10,035	9,266
Fair value related to derivative payables	48,708	44,534
Carrying value of derivative trading liabilities	13,347	11,819
Commodity
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	60,925	51,898
Carrying value of derivative trading assets	10,284	10,635
Fair value related to derivative payables	64,639	55,738
Carrying value of derivative trading liabilities	12,091	12,826
Not Designated as Hedging Instrument
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	1,518,080	1,664,150
Fair value related to derivative payables	1,502,119	1,643,658
Not Designated as Hedging Instrument | Interest rate contract
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	1,168,894	1,323,184
Fair value related to derivative payables	1,131,880	1,284,494
Not Designated as Hedging Instrument | Credit derivatives
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	103,399	100,310
Fair value related to derivative payables	101,350	100,027
Not Designated as Hedging Instrument | Foreign exchange
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	139,523	146,682
Fair value related to derivative payables	155,613	159,509
Not Designated as Hedging Instrument | Equity
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	46,438	42,662
Fair value related to derivative payables	48,708	44,534
Not Designated as Hedging Instrument | Commodity
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	59,826	51,312
Fair value related to derivative payables	64,568	55,094
Designated as Hedging Instrument
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	7,962	8,227
Fair value related to derivative payables	3,688	5,897
Designated as Hedging Instrument | Interest rate contract
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	4,895	6,064
Fair value related to derivative payables	2,816	3,120
Designated as Hedging Instrument | 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 | Foreign exchange
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	1,968	1,577
Fair value related to derivative payables	801	2,133
Designated as Hedging Instrument | 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 | Commodity
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	1,099	586
Fair value related to derivative payables	$ 71	$ 644