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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 |  |  |  |

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