Derivative Financial Instruments (Details 5) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	$ 321	$ 299	$ 28	$ 272
Net Derivatives Gains (Losses) Recognized for Hedged Items	(322)	(290)	(36)	(270)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	(1)	9	(8)	2
Interest rate swaps [Member] | Fixed maturity securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	(10)	(16)	(4)	(5)
Net Derivatives Gains (Losses) Recognized for Hedged Items	9	15	3	5
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	(1)	(1)	(1)	0
Interest rate swaps [Member] | Policyholder account balances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	414	157	114	43
Net Derivatives Gains (Losses) Recognized for Hedged Items	(406)	(150)	(105)	(34)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	8	7	9	9
Foreign currency swaps [Member] | Foreign-denominated fixed maturity securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	(1)	0	1	(1)
Net Derivatives Gains (Losses) Recognized for Hedged Items	1	0	(1)	1
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	(133)	158	(76)	235
Net Derivatives Gains (Losses) Recognized for Hedged Items	124	(155)	61	(242)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	(9)	3	(15)	(7)
Foreign currency forwards [Member] | Foreign-denominated fixed maturity securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	51	0	(7)	0
Net Derivatives Gains (Losses) Recognized for Hedged Items	(50)	0	6	0
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	$ 1	$ 0	$ (1)	$ 0