Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2019	Jan. 21, 2020	Apr. 30, 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-K
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Document Period End Date	Oct. 31, 2019
Amendment Flag	false
Current Fiscal Year End Date	--10-31
Is Entity a Well-known Seasoned Issuer?	No
Is Entity a Voluntary Filer?	No
Entitys Reporting Status Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Public Float			$ 95
Entity Common Stock, Shares Outstanding		6,787,540
Entity Interactive Data Current	Yes
Entity Incorporation State Country Name	NJ
Entity File Number	000-25043