Investments and Derivative Instruments Level 4 Fair Value Hedges (Details) - Fair Value Hedging [Member] - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Fair Value Hedges [Line Items]
Derivative Instruments Gain (Loss) Recognized in Income on Derivative Item Net	[1]	$ 0	$ 1	$ 0	$ (1)
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	[1]	0	(1)	0	2
Gain (Loss) on Investments [Member] | Interest Rate Swap [Member]
Fair Value Hedges [Line Items]
Derivative Instruments Gain (Loss) Recognized in Income on Derivative Item Net	[1]	0	1	0	(1)
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	[1]	$ 0	$ (1)	$ 0	$ 2

[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.