Variable Interest Entities ("VIE's") (Consolidated Variable Interest Entity Settlement Payments and Mark-to-Market Adjustments) (Details) - Derivative Instruments Not Designated And Not Qualifying As Hedging Instruments [Member] - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Consolidated Variable Interest Entity Settlement Payments And Mark To Market Adjustments [Line Items]
Gains (losses) for consolidated variable interest entities	[1]	$ 2	$ 12	$ 10	$ 17
Credit Default Swaps [Member]
Consolidated Variable Interest Entity Settlement Payments And Mark To Market Adjustments [Line Items]
Gains (losses) for consolidated variable interest entities		$ 2	$ 12	$ 10	$ 17
Contingent Forwards [Member]
Consolidated Variable Interest Entity Settlement Payments And Mark To Market Adjustments [Line Items]
Gains (losses) for consolidated variable interest entities

[1] Reported in realized gain (loss) on our Consolidated Statements of Comprehensive Income (Loss).