Investment Holding Level 4 Variable Interest Entities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Variable Interest Entity [Line Items]
Securities Loaned	$ 435	$ 15
Variable Interest Entity, Nonconsolidated, Comparison of Carrying Amount of Assets and Liabilities to Maximum Loss Exposure	859	729
Variable Interest Entity, Consolidated, Carrying Amount, Assets	0	54
Cash	0	12
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	$ 0	$ 43
Variable Interest Entity, Commitments by Third Parties, Liquidity and Other Arrangements	497	299
Securities Held as Collateral, at Fair Value	$ 420	$ 15
Fixed Income Funds [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	0	52
Cash	0	11
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	0	42
Partnership Interest [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	0	2
Cash	0	1
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	0	1
Cash [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	0	$ 0
Available-for-sale Securities Pledged as Collateral	$ 9