Document and Entity Information - shares	6 Months Ended
	Mar. 31, 2018	May 01, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	MONMOUTH REAL ESTATE INVESTMENT CORP
Entity Central Index Key	0000067625
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		79,200,278
Trading Symbol	MNR
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2018