RETIREMENT PLANS (Tables)

9 Months Ended

Jun. 30, 2017

Compensation and Retirement Disclosure [Abstract]

Schedule of components of net periodic benefit cost

The following tables detail the components of net periodic benefit cost for Barnwell’s retirement plans:

	Pension Plan						SERP						Postretirement Medical
	Three months ended June 30,
	2017			2016			2017			2016			2017		2016
Service cost	$	34,000		$	65,000		$	(5,000	)	$	19,000		$	—	$	—
Interest cost	78,000			91,000			1,000			24,000			22,000		14,000
Expected return on plan assets	(122,000		)	(139,000		)	—			—			—		—
Amortization of prior service cost (credit)	2,000			2,000			(2,000		)	(2,000		)	—		—
Amortization of net actuarial loss	21,000			38,000			(17,000		)	12,000			47,000		—
Net periodic benefit cost	$	13,000		$	57,000		$	(23,000	)	$	53,000		$	69,000	$	14,000

	Pension Plan						SERP						Postretirement Medical
	Nine months ended June 30,
	2017			2016			2017			2016			2017		2016
Service cost	$	178,000		$	195,000		$	26,000		$	51,000		$	—	$	—
Interest cost	252,000			273,000			42,000			64,000			66,000		42,000
Expected return on plan assets	(404,000		)	(363,000		)	—			—			—		—
Amortization of prior service cost (credit)	4,000			4,000			(4,000		)	(4,000		)	—		—
Amortization of net actuarial loss	103,000			106,000			—			21,000			141,000		—
Net periodic benefit cost	$	133,000		$	215,000		$	64,000		$	132,000		$	207,000	$	42,000