Investments - Commerical Mortgage Loans by Property Type and Geographic Region (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	$ 2,081	$ 2,252
Commercial mortgage loans maturing in 2015	247
Commercial mortgage loans maturing in 2016	533
Commercial mortgage loans maturing in 2017	229
Commercial mortgage loans maturing in 2018	179
Commercial mortgage loans maturing after 2018	893
Commercial Mortgage Loans Commitments To Extend Credit	65
Pacific Region [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	637	805
South Atlantic Region [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	572	564
New England Region [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	277	379
Central Region [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	214	260
Middle Atlantic [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	287	201
Mountain [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	94	43
Office Buildings [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	700	761
Apartment Buildings [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	264	321
Industrial [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	466	450
Hotels [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	351	407
Retail Facilities [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	272	285
Other Property [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	$ 28	$ 28

Commitments to extend credit under commercial mortgage loan agreements.

No definition available.

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- Definition

Amount of mortgage loans maturing after the fourth fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Amount of mortgage loans maturing in the forth fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

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- Definition

Amount of mortgage loans maturing in the third fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

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- Definition

Amount of mortgage loans maturing in the second fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

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- Definition

Amount of mortgage loans maturing in the next fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

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- Definition

The balance represents the amount of loans that are secured by real estate mortgages, offset by the reserve to cover probable credit losses on the loan portfolio.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.1(c))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Subparagraph c

-Article 7

+ Details

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