Investment Holding Level 4 Variable Interest Entities (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Variable Interest Entity [Line Items]
Percentage of Gross Unrealized Losses Depressed Less than Twenty Percent of Cost or Amortized Cost	94.00%
Variable Interest Entity, Nonconsolidated, Comparison of Carrying Amount of Assets and Liabilities to Maximum Loss Exposure [Abstract]
Variable Interest Entity, Nonconsolidated, Comparison of Carrying Amount of Assets and Liabilities to Maximum Loss Exposure	$ 812,000,000	$ 859,000,000
Variable Interest Entity, Commitments by Third Parties, Liquidity and Other Arrangements	As of June 30, 2017 and December 31, 2016, the Company has outstanding commitments totaling $503 and $497, respectively, whereby the Company is committed to fund these investments and may be called by the partnership during the commitment period to fund the purchase of new investments and partnership expenses. These investments are generally of a passive nature in that the Company does not take an active role in management.	As of June 30, 2017 and December 31, 2016, the Company has outstanding commitments totaling $503 and $497, respectively, whereby the Company is committed to fund these investments and may be called by the partnership during the commitment period to fund the purchase of new investments and partnership expenses. These investments are generally of a passive nature in that the Company does not take an active role in management.
Fixed Income Funds [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$ 0	$ 0