Fair Value Measurements and Disclosures (Details 3) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Net of Unamortized Discount	$ 4,465	[1]	$ 3,797	[1]
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Net of Unamortized Discount	$ 4,959	[1]	$ 4,570	[1]

[1] Excludes capital lease and other obligations. No floating rate debt was outstanding at December 31, 2013 or December 31, 2012. See Note 10. Long-Term Debt.