Investments and Derivative Instruments Level 4 Fair Value Hedges (Details) - Gain (Loss) on Investments [Member] - Fair Value Hedging [Member] - Interest Rate Swap [Member] - Designated as Hedging Instrument [Member] - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014	[1]	Sep. 30, 2015	Sep. 30, 2014
Derivatives, Fair Value [Line Items]
Derivative Instruments Gain (Loss) Recognized in Income on Hedged Item Net	$ 0		$ (2)		$ 0	$ (1)
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	$ 0	[1]	$ 2		$ 0	$ 0

[1] The amounts presented do not include the periodic net coupon settlements of the derivative or the coupon income (expense) related to the hedged item. The net of the amounts presented represents the ineffective portion of the hedge.