CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net earnings (loss)	$ 743	$ (419)
Other comprehensive (loss) income:
Foreign currency translation adjustments, net of taxes of $0	(234)	5
Retirement plans:
Amortization of accumulated other comprehensive loss into net periodic benefit cost, net of taxes of $0	33	60
Net actuarial gains arising during the period, net of taxes of $0	0	880
Curtailment gain, net of taxes of $0	0	1,699
Total other comprehensive (loss) income	(201)	2,644
Total comprehensive income	542	2,225
Less: Comprehensive (income) loss attributable to non-controlling interests	(159)	5
Comprehensive income attributable to Barnwell Industries, Inc.	$ 383	$ 2,230