Investment Holding Level 4 Variable Interest Entities (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Variable Interest Entity [Line Items]
Gain (Loss) on Investments, Excluding Other than Temporary Impairments	$ 89	$ 60		$ 70	$ (72)
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	1,700			$ 1,700		$ 1,700
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 $1.1 billion and $1.2 billion, 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.	As of June 30, 2017 and December 31, 2016, the Company has outstanding commitments totaling $1.1 billion and $1.2 billion, 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.
Collateralized Debt Obligations [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets						5
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities						5
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount						0
Partnership Interest [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	0			$ 0		0
Other Liabilities [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	$ 0			$ 0		5
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets						1
Variable Interest Entity, Nonconsolidated, Carrying Amount, Liabilities						3
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount						$ 3