BUSINESS SEGMENTS - Segment EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ 74,640	$ 55,160
Depreciation and amortization	(15,266)	(15,825)
Income before taxes	39,169	16,951
Operating Segments
Segment Reporting Information [Line Items]
Adjusted EBITDA	86,667	67,102
Depreciation and amortization	(15,216)	(15,675)
Operating Segments \| Consumer and Professional Products
Segment Reporting Information [Line Items]
Adjusted EBITDA	32,713	21,926
Depreciation and amortization	(8,199)	(8,231)
Operating Segments \| Home and Building Products
Segment Reporting Information [Line Items]
Adjusted EBITDA	48,369	40,701
Depreciation and amortization	(4,341)	(4,800)
Operating Segments \| Defense Electronics
Segment Reporting Information [Line Items]
Adjusted EBITDA	5,585	4,475
Depreciation and amortization	(2,676)	(2,644)
Segment Reconciling Items
Segment Reporting Information [Line Items]
Unallocated Expenses	(12,027)	(11,942)
Net interest expense	(15,645)	(15,950)
Depreciation and amortization	(15,266)	(15,825)
Restructuring charges	(10,800)	(6,434)
Gain on sale of SEG business	$ 6,240	$ 0

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Unallocated Expenses

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The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.

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Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

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The net amount of operating interest income (expense).

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Amount, after cash payment, of expenses associated with exit or disposal activities pursuant to an authorized plan and expenses resulting from the write-down of assets. Excludes expenses related to a business combination, a discontinued operation or an asset retirement obligation.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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