Financial and Derivative Instruments (Details 2) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Offsetting Assets [Abstract]
Derivative Assets, Gross Amount Recognized	$ 1,119	$ 4,004
Derivative Assets, Gross Amounts Offset	1,074	3,591
Derivative Assets, Net Amounts Presented	45	413
Derivative Assets, Gross Amounts Not Offset	0	7
Derivative Assets, Net Amount	45	406
Offsetting Liabilities [Abstract]
Derivative Liabilities, Gross Amount Recognized	1,154	3,675
Derivative Liabilities, Gross Amounts Offset	1,074	3,591
Derivative Liabilities	80	84
Derivative Liabilities, Gross Amount Not Offset	0	0
Derivative Liabilities, Net Amount	$ 80	$ 84