OTHER COMPREHENSIVE INCOME (LOSS) - Amounts Reclassified from AOCI (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2024	Mar. 31, 2023
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Income (loss) before taxes	$ 88,573		$ (90,159)		$ 148,715	$ (22,139)
Tax expense	(24,430)		27,904		(42,395)	8,586
Net of tax	64,143	$ 42,177	(62,255)	$ 48,702	106,320	(13,553)
Total | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Income (loss) before taxes	(1,469)		(936)		(2,269)	(876)
Tax expense	308		197		476	184
Net of tax	(1,161)		(739)		(1,793)	(692)
Pension and other defined benefit plans | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Income (loss) before taxes	(689)		(945)		(1,378)	(1,889)
Cash flow hedges | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Income (loss) before taxes	$ (780)		$ 9		$ (891)	$ 1,013