Derivative Instruments and Hedging Activities (Details 2) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Offsetting Assets [Abstract]
Derivative Assets, Gross Amount Recognized	$ 1,210	$ 749
Derivative Assets, Gross Amounts Offset	1,130	663
Derivative Assets, Net Amounts Presented	80	86
Derivative Assets, Gross Amounts Not Offset	42	64
Derivative Assets, Net Amount	38	22
Offsetting Liabilities [Abstract]
Derivative Liabilities, Gross Amount Recognized	1,248	812
Derivative Liabilities, Gross Amounts Offset	1,130	663
Derivative Liabilities	118	149
Derivative Liabilities, Gross Amount Not Offset	7	5
Derivative Liabilities, Net Amount	$ 111	$ 144