Derivatives (Fair Value Hedges) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	$ (395)	$ 321	$ (675)	$ 28
Net Derivatives Gains (Losses) Recognized for Hedged Items	403	(322)	675	(36)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	8	(1)	0	(8)
Interest rate swaps [Member] | Fixed maturity securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	30	(10)	38	(4)
Net Derivatives Gains (Losses) Recognized for Hedged Items	(30)	9	(38)	3
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	0	(1)	0	(1)
Interest rate swaps [Member] | Policyholder account balances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	(383)	414	(536)	114
Net Derivatives Gains (Losses) Recognized for Hedged Items	381	(406)	533	(105)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	(2)	8	(3)	9
Foreign currency swaps [Member] | Foreign-denominated fixed maturity securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	13	(1)	17	1
Net Derivatives Gains (Losses) Recognized for Hedged Items	(11)	1	(16)	(1)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	2	0	1	0
Foreign currency swaps [Member] | Foreign-denominated policyholder account balances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	(55)	(133)	(194)	(76)
Net Derivatives Gains (Losses) Recognized for Hedged Items	63	124	196	61
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	8	(9)	2	(15)
Foreign currency forwards [Member] | Foreign-denominated fixed maturity securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	0	51	0	(7)
Net Derivatives Gains (Losses) Recognized for Hedged Items	0	(50)	0	6
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	$ 0	$ 1	$ 0	$ (1)