DISCONTINUED OPERATIONS (Details)	3 Months Ended		12 Months Ended
	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2008 unit	Feb. 06, 2018 USD ($)	Nov. 16, 2017 USD ($)	Nov. 15, 2017 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operation, Claims Dispute Settlement		$ 11,050,000
Discontinued Operation, Claims Dispute Settlement, Net Of Tax		$ 8,335,000
Discontinued Operation, Payment Of Claims Dispute Settlement	$ 9,500,000
Disposal Group, Post-Close Adjustment, Gross			$ 9,500,000
Disposal Group, Post-Close Adjustment, Net			7,085,000
Number of units sold | unit						11
Number of closed units | unit						1
Number of merged units | unit						2
Environmental exit costs, costs accrued to date				$ 5,700,000
Installation Services [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue			0	0	$ 0
PPC [Member] | Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal group, including discontinued operation, consideration							$ 465,000,000
PPC [Member] | Discontinued Operations, Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of business			112,964,000
Gain on sale of business net of tax			81,041,000
Plastics [Member] | Discontinued Operations, Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue			0	166,262,000	460,914,000
Disposal group, including discontinued operation, consideration								$ 465,000,000	$ 465,000,000
Gain on sale of business			$ 0	$ 112,964,000	$ 0