Derivatives (Fair Value Hedges) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	$ 189	$ (280)
Net Derivatives Gains (Losses) Recognized for Hedged Items	(176)	272
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	13	(8)
Interest rate swaps [Member] | Fixed maturity securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	1	8
Net Derivatives Gains (Losses) Recognized for Hedged Items	1	(8)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	2	0
Interest rate swaps [Member] | Policyholder account balances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	209	(153)
Net Derivatives Gains (Losses) Recognized for Hedged Items	(204)	152
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	5	(1)
Foreign currency swaps [Member] | Foreign-denominated fixed maturity securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	(4)	4
Net Derivatives Gains (Losses) Recognized for Hedged Items	4	(5)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	0	(1)
Foreign currency swaps [Member] | Foreign-denominated policyholder account balances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	(27)	(139)
Net Derivatives Gains (Losses) Recognized for Hedged Items	32	133
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	5	(6)
Foreign currency forwards [Member] | Foreign-denominated fixed maturity securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	10	0
Net Derivatives Gains (Losses) Recognized for Hedged Items	(9)	0
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	$ 1	$ 0