| Document and Entity Information | Jan. 27, 2021 |
| Document And Entity Information [Line Items] | |
| Entity Registrant Name | EMERSON ELECTRIC CO |
| Amendment Flag | true |
| Entity Central Index Key | 0000032604 |
| Document Type | 8-K/A |
| Document Period End Date | Jan. 27, 2021 |
| Entity Incorporation State Country Code | MO |
| Entity File Number | 1-278 |
| Entity Tax Identification Number | 43-0259330 |
| Entity Address, Address Line One | 8000 West Florissant Avenue |
| Entity Address, City or Town | St. Louis |
| Entity Address, State or Province | MO |
| Entity Address, Postal Zip Code | 63136 |
| City Area Code | (314) |
| Local Phone Number | 553-2000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Amendment Description | As previously disclosed in a Current Report on Form 8-K filed on February 1, 2021, as amended by a Current Report on Form 8-K/A filed on February 5, 2021, Surendralal (Lal) L. Karsanbhai has become Chief Executive Officer and a Director of Emerson Electric Co. (the “Company”), succeeding David N. Farr, effective February 5, 2021. Subsequent to those filings, on February 8, 2021, the Company granted to Mr. Karsanbhai an additional award of 50,000 shares of restricted stock in connection with his appointment as Chief Executive Officer of the Company. The restricted shares were issued under the Company’s 2015 Incentive Shares Plan and cliff vest 10 years from the date of grant |
| Common Stockof 0.50parvaluepershare [Member] | |
| Document And Entity Information [Line Items] | |
| Security Exchange Name | NYSE |
| Security 12b Title | Common Stock, $0.50 par value per share |
| Trading Symbol | EMR |
| M 0 [Member] | |
| Document And Entity Information [Line Items] | |
| Security Exchange Name | NYSEArca |
| A 0.375 Notesdue 2024 [Member] | |
| Document And Entity Information [Line Items] | |
| Security Exchange Name | NYSE |
| Security 12b Title | 0.375% Notes due 2024 |
| Trading Symbol | EMR 24 |
| A 1.250 Notesdue 2025 [Member] | |
| Document And Entity Information [Line Items] | |
| Security Exchange Name | NYSE |
| Security 12b Title | 1.250% Notes due 2025 |
| Trading Symbol | EMR 25A |
| A 2.000 Notesdue 2029 [Member] | |
| Document And Entity Information [Line Items] | |
| Security Exchange Name | NYSE |
| Security 12b Title | 2.000% Notes due 2029 |
| Trading Symbol | EMR 29 |
