| Cover Page | Feb. 04, 2020 |
| Entity Information [Line Items] | |
| Entity Central Index Key | 0000032604 |
| Amendment Flag | false |
| Document Type | 8-K |
| Document Period End Date | Feb. 4, 2020 |
| Entity Registrant Name | Emerson Electric Co. |
| Entity Incorporation, State or 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 |
| NEW YORK STOCK EXCHANGE, INC. [Member] | Common Stock of $0.50 par value per share [Member] | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Common Stock of $0.50 par value per share |
| Trading Symbol | EMR |
| Security Exchange Name | NYSE |
| NEW YORK STOCK EXCHANGE, INC. [Member] | 0.375% Notes due 2024 [Member] | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | 0.375% Notes due 2024 |
| Trading Symbol | EMR 24 |
| Security Exchange Name | NYSE |
| NEW YORK STOCK EXCHANGE, INC. [Member] | 1.250% Notes due 2025 [Member] | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | 1.250% Notes due 2025 |
| Trading Symbol | EMR 25A |
| Security Exchange Name | NYSE |
| NEW YORK STOCK EXCHANGE, INC. [Member] | 2.000% Notes due 2029 [Member] | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | 2.000% Notes due 2029 |
| Trading Symbol | EMR 29 |
| Security Exchange Name | NYSE |
| CHICAGO STOCK EXCHANGE, INC [Member] | Common Stock of $0.50 par value per share [Member] | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Common Stock of $0.50 par value per share |
| Trading Symbol | EMR |
| Security Exchange Name | CHX |
