Goodwill And Other Intangibles (Schedule Of Change In Carry Amount Of Goodwill By Business Segment) (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2019	Sep. 30, 2018
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 6,455	$ 5,316
Acquisitions	210	1,188
Divestitures	(2)
Foreign currency translation and other	(127)	(49)
Goodwill, ending balance	6,536	6,455
Automation Solutions [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	5,355	4,704
Acquisitions	210	696
Divestitures	0
Foreign currency translation and other	(98)	(45)
Goodwill, ending balance	5,467	5,355
Commercial & Residential Solutions [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	1,100	612
Acquisitions	0	492
Divestitures	(2)
Foreign currency translation and other	(29)	(4)
Goodwill, ending balance	1,069	1,100
Climate Technologies [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	670	555
Acquisitions	0	118
Divestitures	0
Foreign currency translation and other	(2)	(3)
Goodwill, ending balance	668	670
Tools & Home Products [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	430	57
Acquisitions	0	374
Divestitures	(2)
Foreign currency translation and other	(27)	(1)
Goodwill, ending balance	$ 401	$ 430

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266

+ Details

Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267

+ Details

Name:	us-gaap_GoodwillAcquiredDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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

Name:	us-gaap_GoodwillRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of increase (decrease) from foreign currency translation adjustments and purchase accounting adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e961-128460

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267

+ Details

Name:	us-gaap_GoodwillTranslationAndPurchaseAccountingAdjustments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of divestiture of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267

+ Details

Name:	us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=emr_AutomationSolutionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=emr_CommercialResidentialSolutionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=emr_ClimateTechnologiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=emr_ToolsHomeProductsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: