Derivative Instruments and Hedging Activities - Offsetting Liabilities (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Derivatives liabilities
Gross Amounts	$ 369	$ 710
Offsetting Amounts	0	0
Net Amounts as Recognized	369	710
Offsetting Amounts Not Netted, Financial Instruments	(141)	(262)
Collateral pledged	(170)	(371)
Net Exposure	58	77
Repurchase agreements
Gross Amounts	940	907
Repurchase Agreement, amount offset in balance sheet	0	0
Net Amounts as Recognized	940	907
Repurchase Agreement, amount not offset	0	0
Offsetting Amounts Not Netted, Collateral Pledged	(940)	(907)
Net Exposure	$ 0	$ 0