Derivative Financial Instruments (Details 5) (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) Recognized for Derivatives	$ 26	$ 711	$ 54	$ 983
Net Derivatives Gains (Losses) Recognized for Hedged Items	(27)	(734)	(63)	(1,004)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	(1)	(23)	(9)	(21)
Interest rate swaps [Member] | Fixed maturity securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	(9)	(26)	(13)	(31)
Net Derivatives Gains (Losses) Recognized for Hedged Items	7	22	10	27
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	(2)	(4)	(3)	(4)
Interest rate swaps [Member] | Policyholder account balances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	(47)	957	67	1,000
Net Derivatives Gains (Losses) Recognized for Hedged Items	51	(944)	(54)	(978)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	4	13	13	22
Foreign currency swaps [Member] | Foreign-denominated fixed maturity securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	(2)	1	(1)	0
Net Derivatives Gains (Losses) Recognized for Hedged Items	2	(1)	1	0
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	0	0	0	0
Foreign currency swaps [Member] | Foreign-denominated policyholder account balances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	66	(221)	(10)	14
Net Derivatives Gains (Losses) Recognized for Hedged Items	(68)	189	(7)	(53)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	(2)	(32)	(17)	(39)
Foreign currency forwards [Member] | Foreign-denominated fixed maturity securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	18	0	11	0
Net Derivatives Gains (Losses) Recognized for Hedged Items	(19)	0	(13)	0
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	$ (1)	$ 0	$ (2)	$ 0