Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Assets:
Investments	$ 48	$ 53
Foreign Exchange Contracts	9	6
Total Assets at Fair Value	57	59
Liabilities:
Foreign Exchange Contracts	15	20
Total Liabilities at Fair Value	15	20
Fair Value of Long Term Debt, excluding Capital Leases
Carrying amount - Liability	7,034	6,173
Fixed Rate Debt, Excluding Capital Leases
Fair Value of Long Term Debt, excluding Capital Leases
Carrying amount - Liability	4,090	4,090
Fair Value - Liability	4,455	4,414
Variable Rate Debt, Excluding Capital Leases
Fair Value of Long Term Debt, excluding Capital Leases
Carrying amount - Liability	2,944	2,083
Fair Value - Liability	2,938	2,095
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)
Assets:
Investments	48	53
Foreign Exchange Contracts	0	0
Total Assets at Fair Value	48	53
Liabilities:
Foreign Exchange Contracts	0	0
Total Liabilities at Fair Value	0	0
Significant Other Observable Inputs (Level 2)
Assets:
Investments	0	0
Foreign Exchange Contracts	9	6
Total Assets at Fair Value	9	6
Liabilities:
Foreign Exchange Contracts	15	20
Total Liabilities at Fair Value	15	20
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
Total Liabilities at Fair Value	$ 0	$ 0