INCOME TAXES - Components of Income (Loss) from Continuing Operations and Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Components of income before income taxes:
United States	$ (42,814)	$ 545,826	$ 817,853
Non-U.S	24,224	41,411	32,437
(Loss) Income before income taxes	(18,590)	587,237	850,290
United States:
Federal	26,763	82,125	110,714
State	9,115	16,012	25,556
Non-U.S:	8,745	12,859	11,261
Current income tax expense	44,623	110,996	147,531
United States:
Federal	(40,278)	4,100	12,670
State	(6,240)	351	1,274
Non-U.S:	(1,520)	(1,082)	(1,085)
Deferred income (benefit) tax expense	(48,038)	3,369	12,860
Income tax expense	$ (3,415)	$ 114,365	$ 160,391