Investments - Commerical Mortgage Loans by Property Type and Geographic Region (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	$ 1,864	$ 2,081
Commercial mortgage loans maturing in 2016	205
Commercial mortgage loans maturing in 2017	143
Commercial mortgage loans maturing in 2018	177
Commercial mortgage loans maturing in 2019	275
Commercial mortgage loans maturing after 2019	1,064
Commercial Mortgage Loans Commitments To Extend Credit	5
Pacific Region [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	738	637
South Atlantic Region [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	366	572
New England Region [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	276	277
Central Region [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	205	214
Middle Atlantic [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	227	287
Mountain [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	52	94
Office Buildings [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	697	700
Apartment Buildings [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	366	264
Industrial [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	322	466
Hotels [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	259	351
Retail Facilities [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	213	272
Other Property [Member]
Mortgage Loans on Real Estate [Line Items]
Commercial Mortgage Loans	$ 7	$ 28

Commitments to extend credit under commercial mortgage loan agreements.

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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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- 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

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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