BUSINESS SEGMENTS - Segment EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ 47,963	$ 42,481	$ 103,123	$ 87,862
Net interest expense	(16,561)	(17,305)	(32,511)	(33,636)
Depreciation and amortization	(15,719)	(15,492)	(31,544)	(30,577)
Loss from debt extinguishment, net	(6,690)	0	(6,690)	0
Income before taxes from continuing operations	2,929	9,684	19,880	23,649
Operating Segments
Segment Reporting Information [Line Items]
Adjusted EBITDA	59,910	53,689	127,012	110,334
Depreciation and amortization	(15,566)	(15,353)	(31,241)	(30,304)
Operating Segments \| Consumer and Professional Products
Segment Reporting Information [Line Items]
Adjusted EBITDA	25,027	28,616	46,953	49,181
Depreciation and amortization	(8,222)	(8,184)	(16,453)	(15,990)
Operating Segments \| Home and Building Products
Segment Reporting Information [Line Items]
Adjusted EBITDA	30,635	20,137	71,336	51,432
Depreciation and amortization	(4,668)	(4,548)	(9,468)	(9,057)
Operating Segments \| Defense Electronics
Segment Reporting Information [Line Items]
Adjusted EBITDA	4,248	4,936	8,723	9,721
Depreciation and amortization	(2,676)	(2,621)	(5,320)	(5,257)
Segment Reconciling Items
Segment Reporting Information [Line Items]
Adjusted EBITDA	(11,947)	(11,208)	(23,889)	(22,472)
Net interest expense	(16,561)	(17,305)	(32,511)	(33,636)
Depreciation and amortization	(15,719)	(15,492)	(31,544)	(30,577)
Loss from debt extinguishment, net	(6,690)	0	(6,690)	0
Restructuring charges	(3,104)	0	(9,538)	0
Acquisition costs	$ (2,960)	$ 0	$ (2,960)	$ 0

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The capitalized costs incurred during the period (excluded from amortization) to purchase, lease or otherwise acquire an unproved property, including costs of lease bonuses and options to purchase or lease properties, the portion of costs applicable to minerals when land including mineral rights is purchased in fee, brokers' fees, recording fees, legal costs, and other costs incurred in acquiring properties.

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