Document and Entity Information - shares	9 Months Ended
	Jul. 31, 2019	Sep. 06, 2019
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	2019
Document Fiscal Period Focus	Q3
Document Period End Date	Jul. 31, 2019
Amendment Flag	false
Current Fiscal Year End Date	--10-31
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		6,785,874
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Shell Company	false