OTHER COMPREHENSIVE INCOME (LOSS) (Details) - Summary of amounts reclassified from accumulated other comprehensive income - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before taxes from continuing operations	$ 82,757	$ 72,178	$ 33,810
Provision (benefit) from income taxes	29,328	26,556	555
Net income	53,429	37,287	125,678
Pension and other defined benefit plans | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before taxes from continuing operations	(4,182)	(902)	(1,397)
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	(2,163)	1,361	657
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	(6,345)	459	(740)
Provision (benefit) from income taxes	(1,332)	96	(155)
Net income	$ (5,013)	$ 363	$ (585)