RETIREMENT PLANS (Tables)

12 Months Ended

Sep. 30, 2017

Retirement Benefits [Abstract]

Schedule of changes in benefit obligations, fair values of plan assets and reconciliations of the funded status of the retirement plans

The following tables detail the changes in benefit obligations, fair values of plan assets and reconciliations of the funded status of the retirement plans:

	Pension						SERP						Postretirement Medical
	September 30,
	2017			2016			2017			2016			2017			2016
Change in Projected Benefit Obligation:
Benefit obligation at beginning of year	$	10,055,000		$	8,683,000		$	2,366,000		$	1,900,000		$	2,486,000		$	1,319,000
Service cost	237,000			261,000			34,000			68,000			—			—
Interest cost	336,000			364,000			56,000			86,000			87,000			56,000
Actuarial (gain) loss	(740,000		)	953,000			(847,000		)	318,000			(533,000		)	1,111,000
Benefits paid	(255,000		)	(206,000		)	(4,000		)	(6,000		)	(11,000		)	—
Benefit obligation at end of year	9,633,000			10,055,000			1,605,000			2,366,000			2,029,000			2,486,000
Change in Plan Assets:
Fair value of plan assets at beginning of year	8,195,000			6,488,000			—			—			—			—
Actual return on plan assets	808,000			813,000			—			—			—			—
Employer contributions	350,000			1,100,000			4,000			6,000			11,000			—
Benefits paid	(255,000		)	(206,000		)	(4,000		)	(6,000		)	(11,000		)	—
Fair value of plan assets at end of year	9,098,000			8,195,000			—			—			—			—
Funded status	$	(535,000	)	$	(1,860,000	)	$	(1,605,000	)	$	(2,366,000	)	$	(2,029,000	)	$	(2,486,000	)

Schedule of amounts recognized in the consolidated balance sheets

	Pension						SERP						Postretirement Medical
	September 30,
	2017			2016			2017			2016			2017			2016
Amounts recognized in the Consolidated Balance Sheets:
Current liabilities	$	—		$	—		$	(4,000	)	$	(5,000	)	$	(15,000	)	$	—
Noncurrent liabilities	(535,000		)	(1,860,000		)	(1,601,000		)	(2,361,000		)	(2,014,000		)	(2,486,000		)
Net amount	$	(535,000	)	$	(1,860,000	)	$	(1,605,000	)	$	(2,366,000	)	$	(2,029,000	)	$	(2,486,000	)
Amounts recognized in accumulated other comprehensive loss (income) before income taxes:
Net actuarial loss (gain)	$	2,374,000		$	3,521,000		$	(50,000	)	$	797,000		$	280,000		$	1,001,000
Prior service cost (credit)	65,000			70,000			(65,000		)	(70,000		)	—			—
Accumulated other comprehensive loss (income)	$	2,439,000		$	3,591,000		$	(115,000	)	$	727,000		$	280,000		$	1,001,000

Schedule of amounts recognized in accumulated other comprehensive (loss) income

	Pension						SERP						Postretirement Medical
	September 30,
	2017			2016			2017			2016			2017			2016
Amounts recognized in the Consolidated Balance Sheets:
Current liabilities	$	—		$	—		$	(4,000	)	$	(5,000	)	$	(15,000	)	$	—
Noncurrent liabilities	(535,000		)	(1,860,000		)	(1,601,000		)	(2,361,000		)	(2,014,000		)	(2,486,000		)
Net amount	$	(535,000	)	$	(1,860,000	)	$	(1,605,000	)	$	(2,366,000	)	$	(2,029,000	)	$	(2,486,000	)
Amounts recognized in accumulated other comprehensive loss (income) before income taxes:
Net actuarial loss (gain)	$	2,374,000		$	3,521,000		$	(50,000	)	$	797,000		$	280,000		$	1,001,000
Prior service cost (credit)	65,000			70,000			(65,000		)	(70,000		)	—			—
Accumulated other comprehensive loss (income)	$	2,439,000		$	3,591,000		$	(115,000	)	$	727,000		$	280,000		$	1,001,000

Schedule of weighted-average assumptions used to determine benefit obligations and net periodic benefit costs

The following table presents the weighted-average assumptions used to determine benefit obligations and net benefit costs:

	Pension		SERP		Postretirement Medical
	Year ended September 30,
	2017	2016	2017	2016	2017	2016
Assumptions used to determine fiscal year-end benefit obligations:
Discount rate	3.75%	3.50%	3.75%	3.50%	3.75%	3.50%
Rate of compensation increase	4.00%	4.00%	4.00%	4.00%	N/A	N/A
Assumptions used to determine net benefit costs (years ended):
Discount rate	3.50%	4.25%	3.50%	4.25%	3.50%	4.25%
Expected return on plan assets	6.50%	7.00%	N/A	N/A	N/A	N/A
Rate of compensation increase	4.00%	4.00%	4.00%	4.00%	N/A	N/A

Schedule of components of net periodic benefit cost

The components of net periodic benefit cost are as follows:

	Pension						SERP						Postretirement Medical
	Year ended September 30,
	2017			2016			2017			2016			2017		2016
Net periodic benefit cost for the year:
Service cost	$	237,000		$	261,000		$	34,000		$	68,000		$	—	$	—
Interest cost	336,000			364,000			56,000			86,000			87,000		56,000
Expected return on plan assets	(539,000		)	(484,000		)	—			—			—		—
Amortization of prior service cost (credit)	6,000			5,000			(6,000		)	(5,000		)	—		—
Amortization of net actuarial loss	138,000			141,000			—			27,000			188,000		—
Net periodic benefit cost	$	178,000		$	287,000		$	84,000		$	176,000		$	275,000	$	56,000

Schedule of amounts that are estimated to be amortized from accumulated other comprehensive loss into net periodic benefit cost in the next fiscal year

The amounts that are estimated to be amortized from accumulated other comprehensive loss into net periodic benefit cost in the next fiscal year are as follows:

	Pension		SERP			Postretirement Medical
Prior service cost (credit)	$	6,000	$	(5,000	)	$	—
Net actuarial loss	86,000		—			11,000
	$	92,000	$	(5,000	)	$	11,000

Schedule of benefits expected to be paid under the retirement plans

The benefits expected to be paid under the retirement plans as of September 30, 2017 are as follows:

	Pension		SERP		Postretirement Medical
Expected Benefit Payments:
Fiscal year ending September 30, 2018	$	301,000	$	4,000	$	15,000
Fiscal year ending September 30, 2019	$	284,000	$	4,000	$	15,000
Fiscal year ending September 30, 2020	$	386,000	$	58,000	$	15,000
Fiscal year ending September 30, 2021	$	404,000	$	59,000	$	42,000
Fiscal year ending September 30, 2022	$	390,000	$	58,000	$	44,000
Fiscal years ending September 30, 2023 through 2027	$	2,521,000	$	531,000	$	315,000

Schedule of assumed health care cost trend rates related to the measurement of postretirement medical obligations

The following table provides the assumed health care cost trend rates related to the measurement of Barnwell’s postretirement medical obligations.

	Year ended September 30,
	2017	2016
Health care cost trend rates assumed for next year	7.50%	7.75%
Ultimate cost trend rate	5.0%	5.0%
Year that the rate reaches the ultimate trend rate	2028	2028

Schedule of effects of one-percentage-point change in the assumed health care cost trend rates

A one-percentage-point change in the assumed health care cost trend rates would have the following effects:

	1-Percentage Point Increase		1-Percentage Point (Decrease)
Effect on total service and interest cost components	$	18,000	$	(15,000	)
Effect on accumulated postretirement benefit obligations	$	464,000	$	(361,000	)

Schedule of year-end target allocation, by asset category, and the actual asset allocations

The Company’s year-end target allocation, by asset category, and the actual asset allocations were as follows:

	Target	September 30,
Asset Category	Allocation	2017	2016
Cash and other	0% - 30%	1%	7%
Fixed income securities	20% - 60%	31%	23%
Equity securities	30% - 70%	68%	70%

Schedule of pension plan assets at fair value

The following tables set forth by level, within the fair value hierarchy, pension plan assets at their fair value:

			Fair Value Measurements Using:
	Carrying Amount as of September 30, 2017		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Financial Assets:
Cash	$	124,000	$	124,000	$	—	$	—
Certificates of deposit	496,000		496,000		—		—
Corporate bonds	210,000		210,000		—		—
Fixed income exchange-traded funds	2,036,000		2,036,000		—		—
Preferred securities	51,000		51,000		—		—
Equity securities exchange-traded funds	553,000		553,000		—		—
Equities	5,628,000		5,628,000		—		—
Total	$	9,098,000	$	9,098,000	$	—	$	—
			Fair Value Measurements Using:
	Carrying Amount as of September 30, 2016		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Financial Assets:
Cash	$	571,000	$	571,000	$	—	$	—
Corporate bonds	316,000		316,000		—		—
Fixed income exchange-traded funds	1,414,000		1,414,000		—		—
Preferred securities	184,000		184,000		—		—
Equity securities exchange-traded funds	818,000		818,000		—		—
Equities	4,892,000		4,892,000		—		—
Total	$	8,195,000	$	8,195,000	$	—	$	—