Fair Value Measurements and Disclosures (Details 3) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long Term Debt Net Of Unamortized Discount	$ 4,915	[1]	$ 4,465	[1]
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long Term Debt Net Of Unamortized Discount	$ 5,524	[1]	$ 4,959	[1]

[1] Excludes capital lease and other obligations.