Derivative Financial Instruments (Schedule of The Fair Values of Derivative Financial Instruments) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	$ 10,425	[1]	$ 9,601	[1]
Fair value of derivative liabilities	10,577	[1]	9,438	[1]
Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	10,366	[1]	9,378	[1]
Fair value of derivative liabilities	10,261	[1]	9,084	[1]
Interest-rate contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	58	[1]	223	[1]
Fair value of derivative liabilities	307	[1]	345	[1]
Derivatives not designated as hedging instruments | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	10,144		9,304
Derivatives not designated as hedging instruments | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	10,254		9,137
Derivatives not designated as hedging instruments | Foreign exchange contracts | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	10,109		9,243
Derivatives not designated as hedging instruments | Foreign exchange contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	10,210		9,067
Derivatives not designated as hedging instruments | Interest-rate contracts | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	34		61
Derivatives not designated as hedging instruments | Interest-rate contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	35		61
Derivatives not designated as hedging instruments | Credit derivative contracts | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	1
Derivatives not designated as hedging instruments | Other derivative contracts | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets			0
Derivatives not designated as hedging instruments | Other derivative contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	9		9
Derivatives designated as hedging instruments | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	281		297
Derivatives designated as hedging instruments | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	323		301
Derivatives designated as hedging instruments | Foreign exchange contracts | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	257		135
Derivatives designated as hedging instruments | Foreign exchange contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	51		17
Derivatives designated as hedging instruments | Interest-rate contracts | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	24		162
Derivatives designated as hedging instruments | Interest-rate contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	$ 272		$ 284

[1] Amounts include all transactions regardless of whether or not they are subject to an enforceable netting arrangement.