Derivatives (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Estimated Fair Value Assets	$ 9,301,000,000		$ 9,301,000,000		$ 13,777,000,000
Estimated Fair Value Liabilities	5,558,000,000		5,558,000,000		5,536,000,000
Maximum Amount of Future Payments under Credit Default Swaps	9,387,000,000		9,387,000,000		8,879,000,000
Estimated Fair Value of Credit Default Swaps	117,000,000		117,000,000		74,000,000
Derivative Instruments, Gain (Loss) [Line Items]
Embedded derivatives	898,000,000	227,000,000	3,661,000,000	673,000,000
Derivative Instrument Detail [Abstract]
Net amounts reclassified into net derivatives gains (losses) on discontinued cash flow hedges	0	(1,000,000)	0	3,000,000
Hedging exposure to variability in future cash flows for specific length of time			8 years		8 years
Accumulated Other Comprehensive Income Loss	600,000,000		600,000,000		1,300,000,000
Deferred net gains (losses) expected to be reclassified to earnings			(25,000,000)
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Loss) (Effective Portion)	0	0	0	0
Immateriality of cash flow effectiveness	0	0	0	0
Cumulative foreign currency translation gain (loss) recorded in accumulated other comprehensive income (loss) for net investment in foreign operations hedges	12,000,000		12,000,000		(98,000,000)
Potential future recoveries available to offset maximum amount of future payments under credit default swaps	81,000,000		81,000,000		150,000,000
Excess securities collateral received on derivatives	47,000,000		47,000,000		0
Excess securities collateral provided on derivatives	389,000,000		389,000,000		290,000,000
Change in fair value of derivatives excluded from the assessment of hedge effectiveness	0	3,000,000	0	3,000,000
Securities collateral received which the company is permitted to sell or repledge, amount that has been sold or repledged	0		0
Over the Counter [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Excess securities collateral received on derivatives	202,000,000		202,000,000		161,000,000
Excess securities collateral provided on derivatives	169,000,000		169,000,000		0
Exchange Traded [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Excess securities collateral received on derivatives	123,000,000		123,000,000		0
Excess securities collateral provided on derivatives	39,000,000		39,000,000		40,000,000
Nonperformance Risk [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Embedded derivatives	(145,000,000)	(534,000,000)	(795,000,000)	(1,200,000,000)
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		0
Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Estimated Fair Value Assets	200,000,000		200,000,000		290,000,000
Estimated Fair Value Liabilities	$ 49,000,000		$ 49,000,000		$ 114,000,000