Derivative Financial Instruments (Schedule of The Fair Values of Derivative Financial Instruments) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	$ 11,630	[1]	$ 9,601	[1]
Fair value of derivative liabilities	11,534	[1]	9,438	[1]
Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	11,559	[1]	9,378	[1]
Fair value of derivative liabilities	11,193	[1]	9,084	[1]
Interest-rate contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	71	[1]	223	[1]
Fair value of derivative liabilities	332	[1]	345	[1]
Derivatives not designated as hedging instruments | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	11,244		9,304
Derivatives not designated as hedging instruments | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	11,244		9,137
Derivatives not designated as hedging instruments | Foreign exchange contracts | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	11,201		9,243
Derivatives not designated as hedging instruments | Foreign exchange contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	11,191		9,067
Derivatives not designated as hedging instruments | Interest-rate contracts | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	43		61
Derivatives not designated as hedging instruments | Interest-rate contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	44		61
Derivatives not designated as hedging instruments | Other derivative contracts | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	0		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	386		297
Derivatives designated as hedging instruments | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	290		301
Derivatives designated as hedging instruments | Foreign exchange contracts | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	358		135
Derivatives designated as hedging instruments | Foreign exchange contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	2		17
Derivatives designated as hedging instruments | Interest-rate contracts | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	28		162
Derivatives designated as hedging instruments | Interest-rate contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	$ 288		$ 284

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