Managed Investment Entities - Narrative (Details) $ in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2017 USD ($)	Mar. 31, 2017 USD ($) collateralizedloanobligation	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Variable Interest Entity [Line Items]
Percentage of investment of most subordinate debt tranche, Minimum		15.00%
Percentage of investment of most subordinate debt tranche, Maximum		64.40%
Number of collateralized loan obligation entities | collateralizedloanobligation		16
Face amount of managed investment entities liabilities purchased by subsidiaries after issuance date			$ 11
Amount paid by subsidiaries to purchase managed investment entities liabilities after issuance date			10
Proceeds received by subsidiaries related to sales and redemptions of managed investment entities liabilities		$ 4	23
Difference between aggregate unpaid principal balance and fair value of CLOs' fixed maturity investments	$ 59	59		$ 75
Difference between aggregate unpaid principal balance and carrying value of CLOs' debt	140	140		159
Carrying amount of CLO loans in default	1	1		1
Aggregate unpaid principal balance of CLO loans in default	8	8		10
Variable interest entity, primary beneficiary
Variable Interest Entity [Line Items]
Aggregate fair value of investment in collateralized loan obligations	230	230	$ 250	$ 216
New Collateralized Loan Obligation Entities
Variable Interest Entity [Line Items]
Face value of liabilities issued by managed investment entities on issuance date	408
Face amount of managed investment entities liabilities purchased by subsidiaries at issuance date	24
Subordinated Debt Obligations | Variable interest entity, primary beneficiary
Variable Interest Entity [Line Items]
Aggregate fair value of investment in collateralized loan obligations	$ 160	$ 160