Document And Entity Information - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2023	Jan. 29, 2024	Apr. 30, 2023
Document Information Line Items
Entity Registrant Name	FIRST REAL ESTATE INVESTMENT TRUST OF NEW JERSEY, INC.
Document Type	10-K
Current Fiscal Year End Date	--10-31
Entity Common Stock, Shares Outstanding		7,449,583
Entity Public Float			$ 87
Amendment Flag	false
Entity Central Index Key	0000036840
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Document Period End Date	Oct. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
ICFR Auditor Attestation Flag	false
Document Annual Report	true
Document Transition Report	false
Entity File Number	000-25043
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	22-1697095
Entity Address, Address Line One	505 Main Street
Entity Address, Address Line Two	Suite 400
Entity Address, City or Town	Hackensack
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07601
City Area Code	(201)
Local Phone Number	488-6400
Entity Interactive Data Current	Yes
Document Financial Statement Error Correction [Flag]	true
Document Financial Statement Restatement Recovery Analysis [Flag]	false
Auditor Firm ID	274
Auditor Name	EisnerAmper LLP
Auditor Location	New York, New York
Common Stock
Document Information Line Items
Trading Symbol	FREVS
Title of 12(b) Security	Common stock, par value $0.01 per share
Security Exchange Name	NONE
Preferred Stock
Document Information Line Items
Title of 12(b) Security	Preferred Stock Purchase Rights