Derivatives and Hedging Notional and fair values of derivative instruments (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Derivative [Line Items]
Derivative Assets	$ 80		$ 210
Derivative Liabilities	93		251
Other Current Assets [Member]
Derivative [Line Items]
Derivative Assets	46		167
Other Noncurrent Assets [Member]
Derivative [Line Items]
Derivative Assets	34		43
Other Current Liabilities [Member]
Derivative [Line Items]
Derivative Liabilities	51		171
Other Noncurrent Liabilities [Member]
Derivative [Line Items]
Derivative Liabilities	42		80
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Notional Amount	1,362		1,544
Derivative Assets	80	[1]	208	[1]
Derivative Liabilities	93	[2]	250	[2]
Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Notional Amount	171		336
Derivative Assets	9	[1]	17	[1]
Derivative Liabilities	0	[2]	0	[2]
Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Notional Amount	1,191		1,208
Derivative Assets	71	[1]	191	[1]
Derivative Liabilities	93	[2]	250	[2]
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Notional Amount	1,577		1,849
Derivative Assets	80	[1]	210	[1]
Derivative Liabilities	93	[2]	251	[2]
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Notional Amount	215		305
Derivative Assets	0	[1]	2	[1]
Derivative Liabilities	$ 0	[2]	$ 1	[2]

[1] Included within Other current assets ($46 million in 2013 and $167 million in 2012) or Other non-current assets ($34 million in 2013 and $43 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)