Derivative Financial Instruments (Details Textuals) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Derivatives, Fair Value [Line Items]
Maximum Amount of Future Payments under Credit Default Swaps	$ 8,687,000,000		$ 8,687,000,000		$ 7,681,000,000
Estimated Fair Value of Credit Default Swaps	60,000,000		60,000,000		(41,000,000)
Derivative Instruments, Gain (Loss) [Line Items]
Embedded derivatives	227,000,000	(2,308,000,000)	673,000,000	(1,759,000,000)
Derivative Instrument Detail [Abstract]
Net amounts reclassified into net derivatives gains (losses) on discontinued cash flow hedges	(1,000,000)	(1,000,000)	3,000,000	(15,000,000)
Amount recognized in net derivatives gains (losses) on the ineffective portion of all cash flow hedges	0	0	0	0
Hedging exposure to variability in future cash flows for specific length of time			9 years	9 years
Deferred net gains (losses) expected to be reclassified to earnings			11,000,000
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Loss) (Effective Portion)	0	0	0	0
Cumulative foreign currency translation gain (loss) recorded in accumulated other comprehensive income (loss) for net investment in foreign operations hedges	(196,000,000)		(196,000,000)		(84,000,000)
Potential future recoveries available to offset maximum amount of future payments under credit default swaps	149,000,000		149,000,000		115,000,000
Cash collateral received for collateral arrangements and obligated to return	8,600,000,000		8,600,000,000		9,500,000,000
Fair Value of Securities Received as Collateral that Can be Resold or Repledged	3,300,000,000		3,300,000,000		2,500,000,000
Estimated fair value of over-the-counter derivatives with credit-contingent provisions in gross liability position	1,000,000,000		1,000,000,000
Additional Collateral Required for Derivatives in Gross Liability Position	437,000,000		437,000,000
Gross derivative asset for which the Company has the contractual right of offset	351,000,000		351,000,000
Securities owned and pledged as collateral for exchange-traded futures	40,000,000		40,000,000		42,000,000
Cash collateral owned and pledged as collateral for exchange-traded futures	556,000,000		556,000,000		680,000,000
Change in fair value of derivatives excluded from the assessment of hedge effectiveness	3,000,000	0	3,000,000	0
Nonperformance Risk [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Embedded derivatives	(534,000,000,000)	2,000,000,000	(1,200,000,000)	2,000,000,000
Hedge Funds [Member]
Derivatives, Fair Value [Line Items]
Maximum Amount of Future Payments under Credit Default Swaps	10,000,000		10,000,000		10,000,000
Estimated Fair Value of Credit Default Swaps	0		0		(1,000,000)
Fixed maturity securities [Member]
Derivatives, Fair Value [Line Items]
Estimated fair value of securities collateral provided for over-the-counter derivatives with credit-contingent provisions in gross liability position	$ 603,000,000		$ 603,000,000