Derivatives (Embedded Derivatives) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	$ 273	$ 418
Embedded Derivative, Fair Value of Embedded Derivative Liability	2,018	3,684
Ceded Guaranteed Minimum Benefit [Member] \| Premiums, reinsurance and other receivables [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	356	439
Direct Guaranteed Minimum Benefit [Member] \| Policyholder account balances [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability	(165)	923
Funds withheld on assumed reinsurance [Member] \| Other invested assets [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	63	66
Assumed Guaranteed Minimum Benefit [Member] \| Policyholder account balances [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability	2,024	2,582
Funds withheld on ceded reinsurance [Member] \| Other liabilities [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability	144	162
Other [Member] \| Other invested assets [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	1	1
Other [Member] \| Policyholder account balances [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability	15	17
Options embedded in debt or equity securities [Member] \| Investments [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	$ (147)	$ (88)

Fair value as of the balance sheet date of the embedded derivative or group of embedded derivatives classified as an asset.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44B

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4B

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624163-113959

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 12-16, 44A, 44B

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44A

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44A, 44B

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

- Definition

Fair value as of the balance sheet date of the embedded derivative or group of embedded derivatives classified as a liability.

+ References

+ Details