PROPERTY, PLANT AND EQUIPMENT - Summary of Property Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	$ 729,880	$ 724,509
Accumulated depreciation and amortization	(439,328)	(431,887)
Total	290,552	292,622
Land, building and building improvements
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	163,841	164,486
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	525,928	520,110
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	$ 40,111	$ 39,913