EMPLOYEE BENEFIT PLANS EMPLOYEE BENEFIT PLANS (Details) - Significant unobservable inputs - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Fair value of plan assets at beginning of fiscal year	$ 145,610
Fair value of plan assets at end of fiscal year	147,145	$ 145,610
Fair Value, Inputs, Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Fair value of plan assets at beginning of fiscal year	8,776	0
Purchases, issuances and settlements	0	7,695
Gains and losses	586	1,081
Fair value of plan assets at end of fiscal year	$ 9,362	$ 8,776