LOSS PER COMMON SHARE - RECONCILIATIONS BETWEEN NET LOSS ATTRIBUTABLE TO STOCKHOLDERS AND COMMON SHARES OUTSTANDING (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Net Loss (Numerator)
Basic	$ (5,565)	$ (961)
Effect of dilutive securities - common stock options and restricted stock units	0	0
Diluted	$ (5,565)	$ (961)
Shares (Denominator)
Basic (in shares)	10,017,997	9,969,856
Effect of dilutive securities - common stock options and restricted stock units (in shares)	0	0
Diluted (in shares)	10,017,997	9,969,856
Per-Share Amount
Basic net loss per common share attributable to Barnwell Industries, Inc. stockholders (in dollars per share)	$ (0.56)	$ (0.10)
Diluted net loss per common share attributable to Barnwell Industries, Inc. stockholders (in dollars per share)	$ (0.56)	$ (0.10)