CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net earnings (loss)	$ 2,314	$ (2,864)
Other comprehensive income (loss):
Foreign currency translation adjustments, net of taxes of $0	147	87
Retirement plans:
Amortization of accumulated other comprehensive loss into net periodic benefit cost, net of taxes of $0	326	168
Net actuarial gains (losses) arising during the period, net of taxes of $0	2,389	(2,053)
Total other comprehensive income (loss)	2,862	(1,798)
Total comprehensive income (loss)	5,176	(4,662)
Less: Comprehensive income attributable to non-controlling interests	1,143	751
Comprehensive income (loss) attributable to Barnwell Industries, Inc.	$ 4,033	$ (5,413)