Derivatives (Fair Value Hedges) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Derivatives	$ 383	$ (851)	$ (39)
Net Derivative Gains (Losses) Recognized for Hedged Items	(377)	874	46
Ineffectiveness Recognized in Net Derivative Gains (Losses)	6	23	7
Interest rate swaps \| Fixed maturity securities
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Derivatives	4	34	2
Net Derivative Gains (Losses) Recognized for Hedged Items	(1)	(33)	(3)
Ineffectiveness Recognized in Net Derivative Gains (Losses)	3	1	(1)
Interest rate swaps \| Policyholder account balances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Derivatives	649	(800)	(72)
Net Derivative Gains (Losses) Recognized for Hedged Items	(635)	807	89
Ineffectiveness Recognized in Net Derivative Gains (Losses)	14	7	17
Foreign currency swaps \| Foreign-denominated fixed maturity securities
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Derivatives	13	13	(1)
Net Derivative Gains (Losses) Recognized for Hedged Items	(11)	(12)	1
Ineffectiveness Recognized in Net Derivative Gains (Losses)	2	1	0
Foreign currency swaps \| Foreign-denominated policyholder account balances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Derivatives	(283)	(98)	32
Net Derivative Gains (Losses) Recognized for Hedged Items	270	112	(41)
Ineffectiveness Recognized in Net Derivative Gains (Losses)	$ (13)	$ 14	$ (9)

Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 25

-Section 50

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5618551-113959

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-Publisher FASB

-Name Accounting Standards Codification

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Amount of gain (loss)recognized in the income statement from the hedging ineffectiveness of a fair value hedge.

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