Insurance (Obligations Under Funding Agreements - Liability and Collateral) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal Home Loan Bank amount of advances by branch for funding agreements	$ 800	$ 300
Collateral pledged relating to obligations under funding agreements	1,200	564
Outstanding Funding Agreements To Certain SPEs	32,300	34,200
Invested Assets Pledged As Collateral	24,168	24,174
Funding Agreements Farmer Mac
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Outstanding Funding Agreements To Certain SPEs	2,550	2,550
Invested Assets Pledged As Collateral	2,639	2,644
Federal Home Loan Bank of New York
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal Home Loan Bank amount of advances by branch for funding agreements	14,245	14,445
Collateral pledged relating to obligations under funding agreements	16,557	16,605
Federal Home Loan Bank of Des Moines
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal Home Loan Bank amount of advances by branch for funding agreements	425	625
Collateral pledged relating to obligations under funding agreements	709	701
Federal Home Loan Bank of Pittsburgh
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal Home Loan Bank amount of advances by branch for funding agreements	450	250
Collateral pledged relating to obligations under funding agreements	$ 590	$ 311

Invested assets pledged as collateral.

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- Definition

Amount of funding agreements outstanding to certain SPEs that have issued debt securities for which payment of interest and principal is secured by such funding agreements.

+ References

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- Definition

Amount of advances from the Federal Home Loan Bank (FHLB).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

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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

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- Definition

Amount of the collateral pledged in support of federal home loan bank advances outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

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