Contingencies and Other Matters (Details) (USD $)	6 Months Ended
Jun. 30, 2013	Mar. 31, 2013
Contingencies And Other Matters Details [Abstract]
Liabilities Required Indemnification Obligations Acquisitions and Dispositions	0
Litigation reserves pre tax		$ 200,000,000
Litigation reserves after tax		130,000,000
Market Value Guarantee [Member]
Guarantee Obligations [Line Items]
Guarantee Obligations, Maximum Exposure, Undiscounted	41,000,000
Guarantee Obligations, Current Carrying Value	3,000,000
Market Value Guarantee [Member] \| Expiring In 2016 [Member]
Guarantee Obligations [Line Items]
Guarantee Obligations, Maximum Exposure, Undiscounted	16,000,000
Market Value Guarantee [Member] \| Expiring In 2022 [Member]
Guarantee Obligations [Line Items]
Guarantee Obligations, Maximum Exposure, Undiscounted	25,000,000
Indemnification Guarantee [Member]
Guarantee Obligations [Line Items]
Guarantee Obligations, Maximum Exposure, Undiscounted	283,000,000
Guarantee Type, Other [Member] \| Retirement And Life Insurance Contracts [Member]
Guarantee Obligations [Line Items]
Guarantee Obligations, Current Carrying Value	524,000,000
Separate Accounts Liability Sold Business Percent Reinsured	15.00%
Guarantee Type, Other [Member] \| Variable Annuity [Member] \| Guaranteed Minimum Income Benefit [Member]
Guarantee Obligations [Line Items]
Guarantee Obligations, Maximum Exposure, Undiscounted	916,000,000
Underlying mutual fund investment values for Guaranteed Minimum Income Benefits	$ 1,100,000,000

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Value of underlying mutual fund investments for guaranteed minimum income benefit contracts

+ References

No definition available.

+ Details

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- Definition

Liabilities recorded for indemnification obligations in connection with acquisition and disposition transactions.

+ References

No definition available.

+ Details

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- Definition

After-tax liability carried to reflect the Company's best estimate of liabilities related pending litigation

+ References

No definition available.

+ Details

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- Definition

Pre-tax liability carried to reflect the Company's best estimate of liabilities related pending litigation

+ References

No definition available.

+ Details

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- Definition

The percentage of separate account assets associated with the sold retirement benefits business that represent the fair value of contract holder funds guaranteed by the Company.

+ References

No definition available.

+ Details

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- Definition

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 9

-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 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

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

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 45

-Paragraph 13

-Subparagraph c

-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

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- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

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

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 45

-Paragraph 13

-Subparagraph b

-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 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

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