Investments (Unconsolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Variable Interest Entity [Line Items]
Carrying Amount Asset	$ 14,913	$ 18,539
Carrying Amount Liability	15,720	18,825
Other limited partnership interests
Variable Interest Entity [Line Items]
Carrying Amount Asset	1,491	1,367
Carrying Amount Liability	2,287	1,646
Real estate joint ventures
Variable Interest Entity [Line Items]
Carrying Amount Asset	17	35
Carrying Amount Liability	22	38
Other Investments [Member]
Variable Interest Entity [Line Items]
Carrying Amount Asset	60	58
Carrying Amount Liability	66	62
Structured securities
Variable Interest Entity [Line Items]
Carrying Amount Asset	12,809	16,454
Carrying Amount Liability	12,809	16,454
U.S. and foreign corporate
Variable Interest Entity [Line Items]
Carrying Amount Asset	536	625
Carrying Amount Liability	$ 536	$ 625

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No definition available.

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Carrying amount of the assets in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph a
-URI http://asc.fasb.org/extlink&oid=64801991&loc=d3e5728-111685

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- Definition

Carrying amount of the liabilities in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary.

+ References

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