Investments and Derivative Instruments Level 4 Repurchase Agreements, Dollar Roll Transactions and Other Collateral Transactions (Details) - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Repurchase Agreements, Dollar Roll Transactions and Other Collateral Transactions [Line Items]
Secured Debt, Repurchase Agreements		$ 0
Interest-bearing Deposit Liabilities, Domestic	$ 2,700,000,000	2,500,000,000
Secured Debt, Dollar Rolls	0	0
US Treasury Securities [Member]
Repurchase Agreements, Dollar Roll Transactions and Other Collateral Transactions [Line Items]
Available-for-sale Securities Pledged as Collateral	35,000,000	$ 34,000,000
Fixed Maturities [Member]
Repurchase Agreements, Dollar Roll Transactions and Other Collateral Transactions [Line Items]
Available-for-sale Securities Pledged as Collateral	315,000,000
Other Liabilities [Member]
Repurchase Agreements, Dollar Roll Transactions and Other Collateral Transactions [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	$ 315,000,000