Financial Instruments (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Four Quarter Rolling Average of Notional Amount of Foreign Exchange Contracts Hedging Foreign Currency Transactions	$ 14,500,000,000		$ 13,900,000,000
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	18,000,000	26,000,000
Payments for (Proceeds from) Derivative Instrument, Investing Activities	$ (569,000,000)	$ 113,000,000