Derivatives and Hedging Offsetting of financial liabilities and derivative liabilities (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Derivative [Line Items]
Gross Amounts of Recognized Liabilities	$ 93		$ 251
Gross Amounts Offset in the Statement of Financial Position	(30)		(160)
Net Amounts of Liabilities Presented in the Statement of Financial Position (2)	63	[1]	91	[1]
Other Current Liabilities [Member]
Derivative [Line Items]
Gross Amounts of Recognized Liabilities	51		171
Net Amounts of Liabilities Presented in the Statement of Financial Position (2)	23		23
Other Noncurrent Liabilities [Member]
Derivative [Line Items]
Gross Amounts of Recognized Liabilities	42		80
Net Amounts of Liabilities Presented in the Statement of Financial Position (2)	40		68
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Gross Amounts of Recognized Liabilities	93	[2]	250	[2]
Gross Amounts Offset in the Statement of Financial Position	(30)		(160)
Net Amounts of Liabilities Presented in the Statement of Financial Position (2)	63	[1]	90	[1]
Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Gross Amounts of Recognized Liabilities	0	[2]	0	[2]
Gross Amounts Offset in the Statement of Financial Position	0		0
Net Amounts of Liabilities Presented in the Statement of Financial Position (2)	0	[1]	0	[1]
Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Gross Amounts of Recognized Liabilities	93	[2]	250	[2]
Gross Amounts Offset in the Statement of Financial Position	(30)		(160)
Net Amounts of Liabilities Presented in the Statement of Financial Position (2)	63	[1]	90	[1]
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Gross Amounts of Recognized Liabilities	93	[2]	251	[2]
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Gross Amounts of Recognized Liabilities	0	[2]	1	[2]
Gross Amounts Offset in the Statement of Financial Position	0		0
Net Amounts of Liabilities Presented in the Statement of Financial Position (2)	$ 0	[1]	$ 1	[1]

[1] Included within Other current liabilities ($23 million in both 2013 and 2012) or Other non-current liabilities ($40 million in 2013 and $68 million in 2012)

[2] Included within Other liabilities $51 million in 2013 and $171 million in 2012) or Other non-current liabilities ($42 million in 2013 and $80 million in 2012)