Long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 41
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e9038-108599

+ Details

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

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

+ Details

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

- 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.

+ Details

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

- Details

Name:	srt_StatementGeographicalAxis=country_US
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=country_CN
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidationItemsAxis=srt_ReportableGeographicalComponentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=srt_AmericasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=emr_AsiaMiddleEastAfricaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=srt_EuropeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- 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:

Business Segments Information (Financial Information By Geographic Area) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Net sales	$ 4,558	$ 3,914	$ 4,162	$ 4,151	$ 4,971	$ 4,684	$ 4,570	$ 4,147	$ 16,785	$ 18,372	$ 17,408
United States
Segment Reporting Information [Line Items]
Net sales									7,420	8,390	7,939
Property, Plant and Equipment	2,124				2,128				2,124	2,128	2,027
China
Segment Reporting Information [Line Items]
Net sales									1,845	1,962	1,955
Reportable Geographical Components [Member]
Segment Reporting Information [Line Items]
Net sales									16,798	18,371	17,423
Property, Plant and Equipment	3,688				3,642				3,688	3,642	3,562
Reportable Geographical Components [Member] \| Americas [Member]
Segment Reporting Information [Line Items]
Net sales									8,947	10,103	9,484
Property, Plant and Equipment	2,345				2,339				2,345	2,339	2,234
Reportable Geographical Components [Member] \| Asia, Middle East & Africa
Segment Reporting Information [Line Items]
Net sales									4,854	5,083	5,041
Property, Plant and Equipment	679				671				679	671	652
Reportable Geographical Components [Member] \| Europe [Member]
Segment Reporting Information [Line Items]
Net sales									2,997	3,185	2,898
Property, Plant and Equipment	$ 664				$ 632				664	632	676
Automation Solutions [Member] \| Reportable Geographical Components [Member]
Segment Reporting Information [Line Items]
Net sales									11,155	12,202	11,441
Automation Solutions [Member] \| Reportable Geographical Components [Member] \| Americas [Member]
Segment Reporting Information [Line Items]
Net sales									5,051	5,850	5,517
Automation Solutions [Member] \| Reportable Geographical Components [Member] \| Asia, Middle East & Africa
Segment Reporting Information [Line Items]
Net sales									3,801	3,891	3,657
Automation Solutions [Member] \| Reportable Geographical Components [Member] \| Europe [Member]
Segment Reporting Information [Line Items]
Net sales									2,303	2,461	2,267
Commercial & Residential Solutions [Member] \| Reportable Geographical Components [Member]
Segment Reporting Information [Line Items]
Net sales									5,643	6,169	5,982
Commercial & Residential Solutions [Member] \| Reportable Geographical Components [Member] \| Americas [Member]
Segment Reporting Information [Line Items]
Net sales									3,896	4,253	3,967
Commercial & Residential Solutions [Member] \| Reportable Geographical Components [Member] \| Asia, Middle East & Africa
Segment Reporting Information [Line Items]
Net sales									1,053	1,192	1,384
Commercial & Residential Solutions [Member] \| Reportable Geographical Components [Member] \| Europe [Member]
Segment Reporting Information [Line Items]
Net sales									$ 694	$ 724	$ 631