Debt - Fair Value of Other Financial Instruments (Table) (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term Debt, Fair Value	$ 893	$ 381
Long-term Debt, Fair Value	10,666	11,144
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term Debt, Fair Value	881	396
Long-term Debt, Fair Value	$ 8,043	$ 11,656