Investments and Derivative Instruments (Details 18) (USD $) In Millions, unless otherwise specified							3 Months Ended			3 Months Ended			3 Months Ended			3 Months Ended				3 Months Ended			3 Months Ended			3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 Credit [Member]		Dec. 31, 2013 Credit [Member]		Mar. 31, 2014 Corporate Credit/Foreign Gov. [Member] Single Name Credit Default Swaps [Member] Investment Grade Risk Exposure [Member] Credit [Member]	Mar. 31, 2013 Corporate Credit/Foreign Gov. [Member] Single Name Credit Default Swaps [Member] Investment Grade Risk Exposure [Member] Credit [Member]	Dec. 31, 2013 Corporate Credit/Foreign Gov. [Member] Single Name Credit Default Swaps [Member] Investment Grade Risk Exposure [Member] Credit [Member]	Mar. 31, 2014 Corporate Credit [Member] Single Name Credit Default Swaps [Member] Below Investment Grade Risk Exposure [Member] Credit [Member]	Mar. 31, 2013 Corporate Credit [Member] Single Name Credit Default Swaps [Member] Below Investment Grade Risk Exposure [Member] Credit [Member]	Dec. 31, 2013 Corporate Credit [Member] Single Name Credit Default Swaps [Member] Below Investment Grade Risk Exposure [Member] Credit [Member]	Mar. 31, 2014 Corporate Credit [Member] Basket Credit Default Swaps [Member] Investment Grade Risk Exposure [Member] Credit [Member]	Mar. 31, 2013 Corporate Credit [Member] Basket Credit Default Swaps [Member] Investment Grade Risk Exposure [Member] Credit [Member]	Dec. 31, 2013 Corporate Credit [Member] Basket Credit Default Swaps [Member] Investment Grade Risk Exposure [Member] Credit [Member]	Mar. 31, 2014 Corporate Credit [Member] Basket Credit Default Swaps [Member] Below Investment Grade Risk Exposure [Member] Credit [Member]		Mar. 31, 2013 Corporate Credit [Member] Basket Credit Default Swaps [Member] Below Investment Grade Risk Exposure [Member] Credit [Member]	Dec. 31, 2013 Corporate Credit [Member] Basket Credit Default Swaps [Member] Below Investment Grade Risk Exposure [Member] Credit [Member]	Mar. 31, 2014 Corporate Credit [Member] Embedded Credit Derivatives [Member] Investment Grade Risk Exposure [Member] Credit [Member]	Mar. 31, 2013 Corporate Credit [Member] Embedded Credit Derivatives [Member] Investment Grade Risk Exposure [Member] Credit [Member]	Dec. 31, 2013 Corporate Credit [Member] Embedded Credit Derivatives [Member] Investment Grade Risk Exposure [Member] Credit [Member]	Mar. 31, 2014 CMBS Credit [Member] Basket Credit Default Swaps [Member] Investment Grade Risk Exposure [Member] Credit [Member]	Mar. 31, 2013 CMBS Credit [Member] Basket Credit Default Swaps [Member] Investment Grade Risk Exposure [Member] Credit [Member]	Dec. 31, 2013 CMBS Credit [Member] Basket Credit Default Swaps [Member] Investment Grade Risk Exposure [Member] Credit [Member]	Mar. 31, 2014 CMBS Credit [Member] Basket Credit Default Swaps [Member] Below Investment Grade Risk Exposure [Member] Credit [Member]	Dec. 31, 2013 CMBS Credit [Member] Basket Credit Default Swaps [Member] Below Investment Grade Risk Exposure [Member] Credit [Member]
Derivative [Line Items]
Notional amount	$ 141,307	$ 159,441	$ 4,894	[1],[2]	$ 5,768	[1],[2]	$ 466		$ 1,259	$ 24		$ 24	$ 3,468		$ 3,447	$ 60	[1],[2],[3]		$ 327	$ 350		$ 350	$ 331		$ 166	$ 195	$ 195
Fair Value	(591)	(737)	366	[1]	374	[1]	7		8	0		0	50		50	4	[1],[3]		(7)	338		339	(5)		15	(28)	(31)
Weighted Average Years to Maturity							3 years	1 year		4 months	1 year		3 years	3 years		5 years	[1],[3]	3 years		3 years	3 years		3 years	5 years		3 years	3 years
Underlying Referenced Credit Obligation Type							Corporate Credit/ Foreign Gov.	Corporate Credit/ Foreign Gov.		Corporate Credit	Corporate Credit		Corporate Credit	Corporate Credit		Corporate Credit		CMBS Credit		Corporate Credit	Corporate Credit		CMBS Credit			CMBS Credit	CMBS Credit
Average Credit Rating							A-	A-		CCC	CCC		BBB+	BBB		B		A		A-	BBB+		AA-	BB-		B	B-
Offsetting Notional Amount			3,170	[1],[4]	3,882	[1],[4]	282		1,066	24		24	2,343		2,270	0			327	0		0	326			195	195
Offsetting Fair Value			$ (7)	[1],[4]	$ (7)	[1],[4]	$ (7)		$ (9)	$ 0		$ (1)	$ (34)		$ (35)	$ 0			$ 7	$ 0		$ 0	$ 6			$ 28	$ 31

[1] he 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.[

[2] otional amount is equal to the maximum potential future loss amount. These derivatives are governed by agreements and 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. [

[3] ncludes $4.1 billion and $4.1 billion as of March 31, 2014 and December 31, 2013, respectively, of standard market indices of diversified portfolios of corporate issuers referenced through credit default swaps. These swaps are subsequently valued based upon the observable standard market index.

[4] he 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.