Document and Entity Information Document - shares	3 Months Ended
	Dec. 31, 2017	Jan. 31, 2018
Entity Information [Line Items]
Entity Registrant Name	EMERSON ELECTRIC CO
Entity Central Index Key	0000032604
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		634,837,581