OTHER COMPREHENSIVE INCOME (LOSS) - Summary of amounts reclassified from accumulated other comprehensive income (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax	$ (16,836)	$ (39,653)	$ (26,037)
Net income (loss)	(191,558)	79,211	53,429
Pension amortization | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before taxes from continuing operations	(3,379)	(6,292)	(4,182)
Cash flow hedges | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before taxes from continuing operations	4,741	(2,204)	(2,163)
AOCI attributable to parent | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before taxes from continuing operations	1,362	(8,496)	(6,345)
Tax	(286)	1,784	1,332
Net income (loss)	$ 1,076	$ (6,712)	$ (5,013)