INCOME TAXES - COMPONENTS OF INCOME TAX PROVISION (BENEFIT) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Current:
Federal	$ 17,157	$ 691	$ 13,393
State	(874)	(682)	7,716
Deferred:
Federal	54,449	66,623	36,825
State	26,502	18,531	(8,381)
Investment/production tax credits	(278)	(257)	(278)
Income tax provision	$ 96,956	$ 84,906	$ 49,275