Fair Value Measurements Level 4 Credit Standing Adjustment and Behavior Risk Margin (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Derivative, Gain (Loss) on Derivative, Net	[1]	$ (97)	$ 723	$ (1,705)
Credit standing adjustment assumption net of reinsurance [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Derivative, Gain (Loss) on Derivative, Net		(2)	41	492
Gain (Loss) Due to Changes in Assumptions [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Derivative, Gain (Loss) on Derivative, Net		(42)	31	28
GMWB Derivatives, Net [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Behavior Risk Margin		45	74
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		$ (18)	$ (5)	$ 11

[1] [4]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.