Managed Investment Entities - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) collateralizedloanobligation	Dec. 31, 2015 USD ($) collateralizedloanobligation	Dec. 31, 2014 USD ($) collateralizedloanobligation
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	15
Number of collateralized loan obligation entities formed during the period | collateralizedloanobligation	2	2	2
Face amount of managed investment entities liabilities purchased by subsidiaries after issuance date	$ 24
Amount paid by subsidiaries to purchase managed investment entities liabilities after issuance date	17
Proceeds received by subsidiaries related to sales and redemptions of managed investment entities liabilities	115
Proceeds received by subsidiaries related to redemptions of managed investment entities liabilities		$ 77	$ 81
Number of collateralized loan obligation entities that were substantially liquidated during the period | collateralizedloanobligation			4
Difference between aggregate unpaid principal balance and fair value of CLOs' fixed maturity investments	75	214
Difference between aggregate unpaid principal balance and fair value of CLOs' debt	159	205
Carrying amount of CLO loans in default	1	1
Aggregate unpaid principal balance of CLO loans in default	10	10
Variable interest entity, primary beneficiary
Variable Interest Entity [Line Items]
Aggregate fair value of investment in collateralized loan obligations	216	266	$ 289
New collateralized loan obligation entities
Variable Interest Entity [Line Items]
Face value of liabilities issued by managed investment entities on issuance date	866	869	917
Face amount of managed investment entities liabilities purchased by subsidiaries at issuance date	64	$ 81	94
Subordinated debt obligations | Variable interest entity, primary beneficiary
Variable Interest Entity [Line Items]
Aggregate fair value of investment in collateralized loan obligations	$ 144
Senior debt obligations
Variable Interest Entity [Line Items]
Face amount of managed investment entities liabilities purchased by subsidiaries after issuance date			13
Amount paid by subsidiaries to purchase managed investment entities liabilities after issuance date			$ 13