Managed Investment Entities (Details Textual) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) collateralizedloanobligation	Dec. 31, 2014 USD ($) collateralizedloanobligation	Dec. 31, 2013 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	100.00%
Number of collateralized loan obligation entities | collateralizedloanobligation	13
Number of collateralized loan obligation entities formed during the period | collateralizedloanobligation	2	2	2
Proceeds received by subsidiaries related to sales and redemptions of managed investment entities liabilities	$ 77
Proceeds received by subsidiaries related to redemptions of managed investment entities liabilities		$ 81	$ 142
Number of collateralized loan obligation entities that were substantially liquidated during the period | collateralizedloanobligation		4	2
Difference between aggregate unpaid principal balance and fair value of CLOs' fixed maturity investments	214	$ 83
Difference between aggregate unpaid principal balance and fair value of CLOs' debt	205	131
Carrying amount of CLO loans in default	1	2
Aggregate unpaid principal balance of CLO loans in default	10	6
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Aggregate fair value of investment in collateralized loan obligations	266	289
New Collateralized Loan Obligation Entities [Member]
Variable Interest Entity [Line Items]
Face value of liabilities issued by managed investment entities on issuance date	869	917	$ 829
Face amount of managed investment entities liabilities purchased by subsidiaries at issuance date	81	94	85
Subordinated Debt Obligations [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Aggregate fair value of investment in collateralized loan obligations	$ 115
Senior Debt Obligations [Member]
Variable Interest Entity [Line Items]
Face amount of managed investment entities liabilities purchased by subsidiaries after issuance date		13	94
Amount paid by subsidiaries to purchase managed investment entities liabilities after issuance date		$ 13	$ 89