Derivatives (Fair Value Hedges) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	$ (9)	$ 26	$ (684)	$ 54
Net Derivatives Gains (Losses) Recognized for Hedged Items	14	(27)	689	(63)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	5	(1)	5	(9)
Interest rate swaps [Member] | Fixed maturity securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	(3)	(9)	35	(13)
Net Derivatives Gains (Losses) Recognized for Hedged Items	3	7	(35)	10
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	0	(2)	0	(3)
Interest rate swaps [Member] | Policyholder account balances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	(102)	(47)	(638)	67
Net Derivatives Gains (Losses) Recognized for Hedged Items	105	51	638	(54)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	3	4	0	13
Foreign currency swaps [Member] | Foreign-denominated fixed maturity securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	(7)	(2)	10	(1)
Net Derivatives Gains (Losses) Recognized for Hedged Items	6	2	(10)	1
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	(1)	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	103	66	(91)	(10)
Net Derivatives Gains (Losses) Recognized for Hedged Items	(100)	(68)	96	(7)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	3	(2)	5	(17)
Foreign currency forwards [Member] | Foreign-denominated fixed maturity securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	0	18	0	11
Net Derivatives Gains (Losses) Recognized for Hedged Items	0	(19)	0	(13)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	$ 0	$ (1)	$ 0	$ (2)