Document and Entity Information - shares	9 Months Ended
	Jul. 31, 2018	Sep. 07, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	FIRST REAL ESTATE INVESTMENT TRUST OF NEW JERSEY
Entity Central Index Key	0000036840
Document Type	10-Q
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q3
Document Period End Date	Jul. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--10-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		6,756,734