Financial Instruments (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative [Line Items]
Maturity of Foreign Currency Derivatives	May 31, 2024
Other comprehensive income (loss), foreign currency transaction and translation gain (loss) arising during period, net of tax	$ (1,746,000,000)	$ (1,876,000,000)	$ 15,000,000
Foreign Exchange Contract [Member]
Derivative [Line Items]
Foreign exchange contracts, notional amounts	21,900,000,000	16,800,000,000
Derivative gains to be reclassified to earnings	99,000,000
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Foreign exchange contracts, notional amounts	15,400,000,000	11,200,000,000
Gains/(losses) from foreign currency contracts not designated as hedging instruments	(481,000,000)	99,000,000	102,000,000
Foreign Exchange Contract [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Foreign exchange contracts, notional amounts	2,200,000,000	2,300,000,000
Foreign Exchange Contract [Member] | Net Investment Hedging [Member]
Derivative [Line Items]
Foreign exchange contracts, notional amounts	4,300,000,000	3,300,000,000
Other comprehensive income (loss), foreign currency transaction and translation gain (loss) arising during period, net of tax	$ 952,000,000	$ (285,000,000)	$ (95,000,000)