CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($)	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net loss	$ (419,000)	$ (4,573,000)
Other comprehensive income (loss):
Foreign currency translation adjustments, net of taxes of $0	5,000	(413,000)
Retirement plans:
Amortization of accumulated other comprehensive loss into net periodic benefit cost, net of taxes of $0	60,000	17,000
Net actuarial gains arising during the period, net of taxes of $0	880,000	0
Curtailment gain, net of taxes of $0	1,699,000	0
Total other comprehensive income (loss)	2,644,000	(396,000)
Total comprehensive income (loss)	2,225,000	(4,969,000)
Less: Comprehensive (loss) income attributable to non-controlling interests	(5,000)	27,000
Comprehensive income (loss) attributable to Barnwell Industries, Inc.	$ 2,230,000	$ (4,996,000)