Cover - shares	3 Months Ended
	Dec. 31, 2025	Feb. 18, 2026
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Dec. 31, 2025
Document Transition Report	false
Entity File Number	1-5103
Entity Registrant Name	BARNWELL INDUSTRIES, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	72-0496921
Entity Address, Address Line One	24 Greenway Plaza
Entity Address, Address Line Two	Suite 1800Q
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77046
City Area Code	713
Local Phone Number	730-7026
Title of 12(b) Security	Common Stock, $0.50 par value
Trading Symbol	BRN
Security Exchange Name	NYSEAMER
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		12,566,314
Entity Central Index Key	0000010048
Current Fiscal Year End Date	--09-30
Document Fiscal Year Focus	2026
Document Fiscal Period Focus	Q1
Amendment Flag	false