Derivative Financial Instruments (Schedule of The Fair Values of Derivative Financial Instruments) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	$ 8,376		$ 11,977	[1]
Fair value of derivative liabilities	8,121	[1]	11,811	[1]
Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	8,318		11,911	[1]
Fair value of derivative liabilities	7,842	[1]	11,471	[1]
Interest-rate contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	56		65	[1]
Fair value of derivative liabilities	269	[1]	331	[1]
Derivatives not designated as hedging instruments | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	8,035		11,582
Derivatives not designated as hedging instruments | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	7,802		11,466
Derivatives not designated as hedging instruments | Foreign exchange contracts | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	8,012		11,552
Derivatives not designated as hedging instruments | Foreign exchange contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	7,771		11,428
Derivatives not designated as hedging instruments | Interest-rate contracts | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	21		29
Derivatives not designated as hedging instruments | Interest-rate contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	21		29
Derivatives not designated as hedging instruments | Other derivative contracts | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	2		1
Derivatives not designated as hedging instruments | Other derivative contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	10		9
Derivatives designated as hedging instruments | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	341		395
Derivatives designated as hedging instruments | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	319		345
Derivatives designated as hedging instruments | Foreign exchange contracts | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	306		359
Derivatives designated as hedging instruments | Foreign exchange contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	71		43
Derivatives designated as hedging instruments | Interest-rate contracts | Other assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	35		36
Derivatives designated as hedging instruments | Interest-rate contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	$ 248		$ 302

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