Retirement Plans (Reconciliation Of Change In Value For Level 3 Assets) (Details) - Fair Value, Level 3 [Member] - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2016	Sep. 30, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Level 3, beginning	$ 371	$ 308
Gains (Losses) on assets held	18	18
Gains (Losses) on assets sold	(20)	(20)
Purchases, sales and settlements, net	36	65
Level 3, ending	$ 405	$ 371

Fair value measurement with unobservable inputs reconciliation recurring basis asset gains losses on assets held.

No definition available.

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- Definition

Fair value measurement with unobservable inputs reconciliation recurring basis asset gains losses on assets sold.

+ References

No definition available.

+ Details

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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- Definition

Amount of purchases, (sales), issuances and (settlements) of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

+ Details

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- Definition

Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

+ Details

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