DISCONTINUED OPERATIONS - Income Statement Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) from discontinued operations	$ 0	$ (8,335)	$ 92,423
Plastics | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	0	166,262
Cost of goods and services	0	132,100
Gross profit	0	34,162
Selling, general and administrative expenses	9,500	26,303
Restructuring charges	0	0
Total operating expenses	9,500	26,303
Income from discontinued operations	(9,500)	7,859
Gain on sale of business	0	112,964
Interest expense, net	0	(155)
Other, net	0	(687)
Total other income (expense)	0	112,122
Income (loss) from discontinued operations	$ (9,500)	$ 119,981