Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Assets:
Investments	$ 53	$ 45
Foreign Exchange Contracts	6	2
Total Assets at Fair Value	59	47
Liabilities:
Foreign Exchange Contracts	20	29
Other Liabilities, Fair Value Disclosure	0	3
Total Liabilities at Fair Value	20	32
Fair Value of Long Term Fixed Rate and Variable Rate Debt, excluding Capital Leases
Carrying amount - liability	6,173	4,926
Fixed Rate Debt, Excluding Capital Leases
Fair Value of Long Term Fixed Rate and Variable Rate Debt, excluding Capital Leases
Carrying amount - liability	4,090	3,128
Fair value - liability	4,414	3,378
Variable Rate Debt, Excluding Capital Leases
Fair Value of Long Term Fixed Rate and Variable Rate Debt, excluding Capital Leases
Carrying amount - liability	2,083	1,798
Fair value - liability	2,095	1,808
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)
Assets:
Investments	53	45
Foreign Exchange Contracts	0	0
Total Assets at Fair Value	53	45
Liabilities:
Foreign Exchange Contracts	0	0
Other Liabilities, Fair Value Disclosure	0	0
Total Liabilities at Fair Value	0	0
Significant Other Observable Inputs (Level 2)
Assets:
Investments	0	0
Foreign Exchange Contracts	6	2
Total Assets at Fair Value	6	2
Liabilities:
Foreign Exchange Contracts	20	29
Other Liabilities, Fair Value Disclosure	0	3
Total Liabilities at Fair Value	20	32
Significant Unobservable Inputs (Level 3)
Assets:
Investments	0	0
Foreign Exchange Contracts	0	0
Total Assets at Fair Value	0	0
Liabilities:
Foreign Exchange Contracts	0	0
Other Liabilities, Fair Value Disclosure	0	0
Total Liabilities at Fair Value	$ 0	$ 0