Fair Value Measurements Level 4 Credit Standing Adjustment and Behavior Risk Margin (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ 723	$ (1,705)	$ (1,922)
Credit standing adjustment assumption net of reinsurance [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Derivative, Gain (Loss) on Derivative, Net	41	492	499
Gain (Loss) Due to Changes in Assumptions [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Derivative, Gain (Loss) on Derivative, Net	31	28	76
GMWB Derivatives, Net [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Behavior Risk Margin	74	32
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	$ (5)	$ 11	$ 29