STOCK-BASED COMPENSATION - NARRATIVE (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance (in shares)	2,774,527
Performance Shares, Market Condition Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted but not issued (in shares)	39,614	44,965	46,813
Performance Shares, Subject to Performance Conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted but not issued (in shares)	73,047	73,561	70,138
Deferred compensation related to unvested performance shares, period	1 year 8 months 12 days
Performance Shares, Subject to Performance Conditions | Vesting September 30, 2025
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted but not issued (in shares)	42,449
Performance Shares, Subject to Performance Conditions | Vesting Annually Over Three Year Period Beginning September 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted but not issued (in shares)	30,598
Award vesting period	3 years
Performance Shares, Subject to Performance Conditions | Vesting September 30, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted but not issued (in shares)		44,596
Performance Shares, Subject to Performance Conditions | Vesting Annually Over Three Year Period Beginning September 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted but not issued (in shares)		28,965
Award vesting period		3 years
Performance Shares, Subject to Performance Conditions | Vesting September 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted but not issued (in shares)			44,156
Performance Shares, Subject to Performance Conditions | Vesting Annually Over Three Year Period Beginning September 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted but not issued (in shares)			25,982
Award vesting period			3 years
Performance share awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted but not issued (in shares)	190,255	192,121	166,091	155,731
Deferred compensation related to unvested restricted and performance shares	$ 5.2
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted but not issued (in shares)	108,876	97,824	101,621	73,486
Deferred compensation related to unvested restricted and performance shares	$ 1.4
Deferred compensation related to unvested performance shares, period	1 year 9 months 18 days
Restricted Stock | Vesting Annually Over Three Year Period Beginning October 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted but not issued (in shares)	64,080
Award vesting period	3 years
Restricted Stock | Vesting Annually Over Three Year Period Beginning October 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted but not issued (in shares)		54,826
Award vesting period		3 years
Restricted Stock | Vesting Annually Over Three Year Period Beginning October 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted but not issued (in shares)			67,726
Award vesting period			3 years