Document and Entity Information Document - shares	6 Months Ended
	Mar. 31, 2018	Apr. 30, 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	Mar. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		630,090,112