RETIREMENT PLANS - CHANGES IN BENEFIT OBLIGATIONS (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Change in Plan Assets:
Fair value of plan assets at beginning of year	$ 11,051
Fair value of plan assets at end of year	12,594	$ 11,051
Amounts recognized in the Consolidated Balance Sheets:
Noncurrent assets	2,229	771
Noncurrent liabilities	(2,101)	(4,829)
Pension Plan
Change in Projected Benefit Obligation:
Benefit obligation at beginning of year	10,280	10,971
Service cost	0	50
Interest cost	258	304
Actuarial (gain) loss	(15)	504
Benefits paid	(158)	(153)
Curtailments	0	(1,396)
Termination of post-retirement medical plan	0	0
Benefit obligation at end of year	10,365	10,280
Change in Plan Assets:
Fair value of plan assets at beginning of year	11,051	10,192
Actual return on plan assets	1,701	1,012
Employer contributions	0	0
Benefits paid	(158)	(153)
Fair value of plan assets at end of year	12,594	11,051
Funded status	2,229	771
Amounts recognized in the Consolidated Balance Sheets:
Noncurrent assets	2,229	771
Current liabilities	0	0
Noncurrent liabilities	0	0
Net amount	2,229	771
Amounts recognized in accumulated other comprehensive income (loss) before income taxes:
Net actuarial loss	471	1,681
Prior service cost (credit)	0	0
Accumulated other comprehensive loss	471	1,681
SERP
Change in Projected Benefit Obligation:
Benefit obligation at beginning of year	2,031	2,385
Service cost	0	3
Interest cost	51	63
Actuarial (gain) loss	63	(90)
Benefits paid	(9)	0
Curtailments	0	(330)
Termination of post-retirement medical plan	0	0
Benefit obligation at end of year	2,136	2,031
Change in Plan Assets:
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contributions	0	0
Benefits paid	0	0
Fair value of plan assets at end of year	0	0
Funded status	(2,136)	(2,031)
Amounts recognized in the Consolidated Balance Sheets:
Noncurrent assets	0	0
Current liabilities	(35)	(32)
Noncurrent liabilities	(2,101)	(1,999)
Net amount	(2,136)	(2,031)
Amounts recognized in accumulated other comprehensive income (loss) before income taxes:
Net actuarial loss	135	72
Prior service cost (credit)	0	0
Accumulated other comprehensive loss	135	72
Post-retirement Medical
Change in Projected Benefit Obligation:
Benefit obligation at beginning of year	2,839	2,633
Service cost	0	0
Interest cost	48	80
Actuarial (gain) loss	0	134
Benefits paid	(5)	(8)
Curtailments	0	0
Termination of post-retirement medical plan	(2,882)	0
Benefit obligation at end of year	0	2,839
Change in Plan Assets:
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contributions	5	8
Benefits paid	(5)	(8)
Fair value of plan assets at end of year	0	0
Funded status	0	(2,839)
Amounts recognized in the Consolidated Balance Sheets:
Noncurrent assets	0	0
Current liabilities	0	(9)
Noncurrent liabilities	0	(2,830)
Net amount	0	(2,839)
Amounts recognized in accumulated other comprehensive income (loss) before income taxes:
Net actuarial loss	0	721
Prior service cost (credit)	0	0
Accumulated other comprehensive loss	$ 0	$ 721