Financial and Derivative Instruments Financial and Derivative Instruments (Details 2) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Offsetting Assets [Abstract]
Derivative Asset, Gross Amount Recognized	$ 732	$ 749
Derivative Asset, Gross Amounts Offset	704	663
Derivative Asset, Net Amounts Presented	28	86
Derivative Assets, Gross Amounts Not Offset	27	64
Derivative Asset, Net Amount	1	22
Offsetting Liabilities [Abstract]
Derivative Liability, Gross Amount Recognized	793	812
Derivative Liability, Gross Amounts Offset	704	663
Derivative Liability, Net Amounts Presented	89	149
Derivative Liabilities, Gross Amounts Not Offset	0	5
Derivative Liability, Net Amount	$ 89	$ 144