Investments and Derivative Instruments Level 4 Credit Derivatives (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Credit Derivatives [Line Items]
Derivative, Notional Amount		$ 62,185	$ 72,850
Derivative, Fair Value, Net		(926)	(639)
Credit Default Swap, Selling Protection [Member]
Credit Derivatives [Line Items]
Derivative, Notional Amount		4,487	4,159	[1],[2]
Single Name Credit Default Swaps [Member] | Credit Default Swap, Selling Protection [Member] | Debt Securities Payable [Member] | Standard & Poor's, BBB+ Rating [Member] | External Credit Rating, Investment Grade [Member]
Credit Derivatives [Line Items]
Derivative, Notional Amount		190	320	[3]
Credit Risk Derivatives, at Fair Value, Net		$ (1)	$ 5
Average Term of Credit Risk Derivatives		1 year	2 years
Single Name Credit Default Swaps [Member] | Credit Default Swap, Selling Protection [Member] | Debt Securities Payable [Member] | Standard & Poor's, BB Rating [Member] | External Credit Rating, Non Investment Grade [Member]
Credit Derivatives [Line Items]
Derivative, Notional Amount		$ 77	$ 29	[3]
Credit Risk Derivatives, at Fair Value, Net		$ (2)	$ 0
Average Term of Credit Risk Derivatives		2 years	2 years
Basket Credit Default Swaps [Member]
Credit Derivatives [Line Items]
Amount of Standard Market Indices of Diversified Portfolios of Corporate Issuers		$ 3,900	$ 3,500
Basket Credit Default Swaps [Member] | Credit Default Swap, Selling Protection [Member] | Debt Securities Payable [Member] | Standard & Poor's, BBB+ Rating [Member] | External Credit Rating, Investment Grade [Member]
Credit Derivatives [Line Items]
Derivative, Notional Amount		3,036	2,546	[3]
Credit Risk Derivatives, at Fair Value, Net		$ 22	$ 33
Average Term of Credit Risk Derivatives		4 years	3 years
Basket Credit Default Swaps [Member] | Credit Default Swap, Selling Protection [Member] | Debt Securities Payable [Member] | Standard & Poor's, B Rating [Member] | External Credit Rating, Non Investment Grade [Member]
Credit Derivatives [Line Items]
Derivative, Notional Amount	[3]		$ 38
Credit Risk Derivatives, at Fair Value, Net			$ (1)
Average Term of Credit Risk Derivatives			12 years
Basket Credit Default Swaps [Member] | Credit Default Swap, Selling Protection [Member] | Collateralized Mortgage Backed Securities [Member] | Standard & Poor's, AA+ Rating [Member] | External Credit Rating, Investment Grade [Member]
Credit Derivatives [Line Items]
Derivative, Notional Amount		$ 681	$ 722	[3]
Credit Risk Derivatives, at Fair Value, Net		$ (19)	$ (12)
Average Term of Credit Risk Derivatives		6 years	6 years
Basket Credit Default Swaps [Member] | Credit Default Swap, Selling Protection [Member] | Collateralized Mortgage Backed Securities [Member] | Standard & Poor's, CCC+ Rating [Member] | External Credit Rating, Non Investment Grade [Member]
Credit Derivatives [Line Items]
Derivative, Notional Amount		$ 153	$ 154	[3]
Credit Risk Derivatives, at Fair Value, Net		$ (25)	$ (22)
Average Term of Credit Risk Derivatives		1 year	2 years
Embedded Derivative Financial Instruments [Member] | Credit Default Swap, Selling Protection [Member] | Debt Securities Payable [Member] | Standard & Poor's, A+ Rating [Member] | External Credit Rating, Investment Grade [Member]
Credit Derivatives [Line Items]
Derivative, Notional Amount		$ 350	$ 350	[2]
Credit Risk Derivatives, at Fair Value, Net		$ 346	$ 342
Average Term of Credit Risk Derivatives		1 year	2 years
Credit [Member]
Credit Derivatives [Line Items]
Derivative, Fair Value, Net		$ 321	$ 345	[1]
Derivative, Fair Value, Amount Offset Against Collateral, Net		13	(5)	[4]
Credit Derivatives in Offsetting Positions [Member] | Credit Default Swap, Selling Protection [Member]
Credit Derivatives [Line Items]
Derivative, Notional Amount		2,029	2,672	[1],[4]
Credit Derivatives in Offsetting Positions [Member] | Single Name Credit Default Swaps [Member] | Credit Default Swap, Selling Protection [Member] | Debt Securities Payable [Member] | Standard & Poor's, BBB+ Rating [Member] | External Credit Rating, Investment Grade [Member]
Credit Derivatives [Line Items]
Derivative, Notional Amount		176	247	[4]
Credit Risk Derivatives, at Fair Value, Net		(1)	(5)	[4]
Credit Derivatives in Offsetting Positions [Member] | Single Name Credit Default Swaps [Member] | Credit Default Swap, Selling Protection [Member] | Debt Securities Payable [Member] | Standard & Poor's, BB Rating [Member] | External Credit Rating, Non Investment Grade [Member]
Credit Derivatives [Line Items]
Derivative, Notional Amount		77	29	[4]
Credit Risk Derivatives, at Fair Value, Net		1	(1)	[4]
Credit Derivatives in Offsetting Positions [Member] | Basket Credit Default Swaps [Member] | Credit Default Swap, Selling Protection [Member] | Debt Securities Payable [Member] | Standard & Poor's, BBB+ Rating [Member] | External Credit Rating, Investment Grade [Member]
Credit Derivatives [Line Items]
Derivative, Notional Amount		1,411	1,973	[4]
Credit Risk Derivatives, at Fair Value, Net		(13)	(25)	[4]
Credit Derivatives in Offsetting Positions [Member] | Basket Credit Default Swaps [Member] | Credit Default Swap, Selling Protection [Member] | Debt Securities Payable [Member] | Standard & Poor's, B Rating [Member] | External Credit Rating, Non Investment Grade [Member]
Credit Derivatives [Line Items]
Derivative, Notional Amount	[4]		0
Credit Risk Derivatives, at Fair Value, Net	[4]		0
Credit Derivatives in Offsetting Positions [Member] | Basket Credit Default Swaps [Member] | Credit Default Swap, Selling Protection [Member] | Collateralized Mortgage Backed Securities [Member] | Standard & Poor's, AA+ Rating [Member] | External Credit Rating, Investment Grade [Member]
Credit Derivatives [Line Items]
Derivative, Notional Amount		212	269	[4]
Credit Risk Derivatives, at Fair Value, Net		1	3	[4]
Credit Derivatives in Offsetting Positions [Member] | Basket Credit Default Swaps [Member] | Credit Default Swap, Selling Protection [Member] | Collateralized Mortgage Backed Securities [Member] | Standard & Poor's, CCC+ Rating [Member] | External Credit Rating, Non Investment Grade [Member]
Credit Derivatives [Line Items]
Derivative, Notional Amount		153	154	[4]
Credit Risk Derivatives, at Fair Value, Net		25	23	[4]
Credit Derivatives in Offsetting Positions [Member] | Embedded Derivative Financial Instruments [Member] | Credit Default Swap, Selling Protection [Member] | Debt Securities Payable [Member] | Standard & Poor's, A+ Rating [Member] | External Credit Rating, Investment Grade [Member]
Credit Derivatives [Line Items]
Derivative, Notional Amount		0	0	[4]
Credit Risk Derivatives, at Fair Value, Net		$ 0	$ 0	[4]

[1] 5]Excludes investments that contain an embedded credit derivative for which the Company has elected the fair value option. For further discussion, see the Fair Value Option section in Note 4 - Fair Value Measurements

[2] [1]The average credit ratings are based on availability and the midpoint of the applicable ratings among Moody’s, S&P, Fitch and Morningstar. If no rating is available from a rating agency, then an internally developed rating is used.

[3] [2]Notional amount is equal to the maximum potential future loss amount. These derivatives are governed by agreements, clearing house rules and applicable law which include collateral posting requirements. There is no additional specific collateral related to these contracts or recourse provisions included in the contracts to offset losses.

[4] [3]The Company has entered into offsetting credit default swaps to terminate certain existing credit default swaps, thereby offsetting the future changes in value of, or losses paid related to, the original swap.