Fair Value Measurements Level 4 Credit Standing Adjustments and Behavior Risk Margin (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2016		Jun. 30, 2015		Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ 22	[1]	$ (13)	[1]	$ 19	$ (40)
Credit standing adjustment asset (liability), net	(1)				(1)		$ 0
Behavior Risk Margin	43				43		45
Credit standing adjustment assumption net of reinsurance [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(3)		(2)		(1)	(2)
Gain (Loss) Due to Changes in Assumptions [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0		0		0	0
Behavior Risk Margin Update Due to Underlying Fund Performance [Member] | GMWB Derivatives, Net [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Derivative, Gain (Loss) on Derivative, Net	17		1		13	11
US Treasury Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	$ 42		$ 0		$ 42	$ 0	$ 166	$ 0

[1] Excludes investments that contain an embedded credit derivative for which the Company has elected the fair value option. For further discussion, see the Fair Value Option section in Note 2 - Fair Value Measurements.