Derivative Instruments - Impact on Balance Sheet (Details 1a) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	$ 1,349,312	$ 1,664,281
Carrying value of derivative trading assets	73,751	74,983
Fair value related to derivative payables	1,332,119	1,641,459
Carrying value of derivative trading liabilities	64,385	70,656
Interest rate contract
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	971,212	1,302,567
Carrying value of derivative trading assets	31,697	39,205
Fair value related to derivative payables	938,185	1,260,719
Carrying value of derivative trading liabilities	18,416	24,906
Credit derivatives
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	93,661	100,310
Carrying value of derivative trading assets	2,364	1,735
Fair value related to derivative payables	91,643	100,027
Carrying value of derivative trading liabilities	2,611	2,504
Foreign exchange
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	177,257	174,940
Carrying value of derivative trading assets	14,317	14,142
Fair value related to derivative payables	193,060	188,537
Carrying value of derivative trading liabilities	16,710	18,601
Equity
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	52,059	42,662
Carrying value of derivative trading assets	13,569	9,266
Fair value related to derivative payables	53,404	44,534
Carrying value of derivative trading liabilities	14,728	11,819
Commodity
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	55,123	43,802
Carrying value of derivative trading assets	11,804	10,635
Fair value related to derivative payables	55,827	47,642
Carrying value of derivative trading liabilities	11,920	12,826
Not Designated as Hedging Instrument
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	1,340,184	1,656,054
Fair value related to derivative payables	1,327,347	1,635,562
Not Designated as Hedging Instrument | Interest rate contract
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	967,026	1,296,503
Fair value related to derivative payables	933,868	1,257,599
Not Designated as Hedging Instrument | Credit derivatives
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	93,661	100,310
Fair value related to derivative payables	91,643	100,027
Not Designated as Hedging Instrument | Foreign exchange
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	174,697	173,363
Fair value related to derivative payables	192,625	186,404
Not Designated as Hedging Instrument | Equity
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	52,059	42,662
Fair value related to derivative payables	53,404	44,534
Not Designated as Hedging Instrument | Commodity
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	52,741	43,216
Fair value related to derivative payables	55,807	46,998
Designated as Hedging Instrument
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	9,128	8,227
Fair value related to derivative payables	4,772	5,897
Designated as Hedging Instrument | Interest rate contract
Impact of derivatives on the Consolidated Balance Sheets [Abstract]
Fair value related to derivative receivables	4,186	6,064
Fair value related to derivative payables	4,317	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	2,560	1,577
Fair value related to derivative payables	435	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	2,382	586
Fair value related to derivative payables	$ 20	$ 644