CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (3,467)	$ (1,398)	$ (5,404)	$ (8,122)
Other comprehensive (loss) income:
Foreign currency translation adjustments, net of taxes of $0	(125)	89	(36)	(194)
Retirement plans:
Amortization of accumulated other comprehensive loss into net periodic benefit cost, net of taxes of $0	20	9	100	42
Net actuarial gains arising during the period, net of taxes of $0	0	0	880	0
Curtailment gain, net of taxes of $0	0	0	1,699	0
Total other comprehensive (loss) income	(105)	98	2,643	(152)
Total comprehensive loss	(3,572)	(1,300)	(2,761)	(8,274)
Less: Comprehensive loss attributable to non-controlling interests	(11)	(33)	(20)	(32)
Comprehensive loss attributable to Barnwell Industries, Inc.	$ (3,561)	$ (1,267)	$ (2,741)	$ (8,242)