Commitments, Contingent Liabilities And Litigation And Regulatory Matters (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Commitments and Guarantees and Contingent Liabilities [Line Items]
Loss contingency, range of possible loss, maximum (less than)	$ 150
Commitments \| Mortgage Loans
Commitments and Guarantees and Contingent Liabilities [Line Items]
Purchase obligation commercial mortgage loan	97	$ 9
Commitments \| Investments
Commitments and Guarantees and Contingent Liabilities [Line Items]
Commitments to fund or purchase investments	$ 135	$ 121

The difference between the maximum amount of estimated loss and the amount recorded as of the balance sheet date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 05
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6395354&loc=d3e12631-108344

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Balance Type:	debit
Period Type:	instant

- Definition

Total carrying amount of mortgage loans as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 10
-Section S99
-Paragraph 6
-Subparagraph (SX 210.5-04.(c) Schedule IV)
-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29.6)
-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

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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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- Definition

Minimum amount of purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier.

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	instant

- Details

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- Details

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- Details

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