LOSS PER COMMON SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Numerator:
Net loss from continuing operations	$ (1,412)	$ (1,600)
Less: Net earnings (loss) attributable to non-controlling interests of continuing operations	14	(2)
Net loss from continuing operations attributable to Barnwell Industries, Inc.	(1,426)	(1,598)
Net (loss) from discontinued operations	0	(319)
Net loss attributable to Barnwell Industries, Inc.	$ (1,426)	$ (1,917)
Denominator:
Basic weighted-average number of common shares outstanding	11,070,498	10,047,173
Effect of dilutive securities - common stock options and restricted stock units	0	0
Diluted weighted-average number of common shares outstanding	11,070,498	10,047,173
Basic and diluted loss per common share attributable to Barnwell Industries, Inc. stockholders:
Basic net loss per common share from continuing operations attributable to Barnwell Industries, Inc. stockholders (in dollars per share)	$ (0.13)	$ (0.16)
Diluted net loss per common share from continuing operations attributable to Barnwell Industries, Inc. stockholders (in dollars per share)	(0.13)	(0.16)
Basic net loss per common share from discontinued operations (in dollars per share)	0	(0.03)
Diluted net loss per common share from discontinued operations (in dollars per share)	0	(0.03)
Basic net loss per common share attributable to Barnwell Industries, Inc. stockholders (in dollars per share)	(0.13)	(0.19)
Diluted net loss per common share attributable to Barnwell Industries, Inc. stockholders (in dollars per share)	$ (0.13)	$ (0.19)
Warrant
Antidilutive shares excluded from the computation of diluted shares
Antidilutive shares excluded from computation of loss per share (in shares)	369,135
Options
Antidilutive shares excluded from the computation of diluted shares
Antidilutive shares excluded from computation of loss per share (in shares)	544,301	465,000
Restricted Stock Units (RSUs)
Antidilutive shares excluded from the computation of diluted shares
Antidilutive shares excluded from computation of loss per share (in shares)	365,142	216,712