Derivative Financial Instruments (Details 13) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Net derivatives gains (losses)	$ 227	$ (2,308)	$ 673	$ (1,759)
Net derivatives gains (losses) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net derivatives gains (losses)	227	(2,308)	673	(1,759)
Policyholder benefits and claims [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net derivatives gains (losses)	$ (4)	$ 113	$ (9)	$ 105