Derivatives and Hedging - Schedule of the amount of gain (loss) recognized in the Consolidated Financial Statements (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Derivative [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative	$ (19)		$ (10)		$ 3
Designated as Hedging Instrument [Member] | Fair Value Hedging [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative	(9)	[1],[2]	(8)	[1],[2]	1	[1],[2]
Amount of Gain (Loss) Recognized in Income on Related Hedged Item	$ 9	[1]	$ 8	[1]	$ (1)	[1]

[1] Included in interest expense

[2] Relates to fixed rate debt