BUSINESS SEGMENTS - Segment EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ 59,554	$ 68,453
Segment adjusted EBITDA	72,511	81,082
Depreciation and amortization	(13,081)	(12,590)
Proxy contest costs	(2,291)	0
Income before taxes from continuing operations	24,223	37,138
Discontinued Operations, Held-for-sale | Defense Electronics
Segment Reporting Information [Line Items]
Defense Electronics	4,472	5,585
Operating Segments
Segment Reporting Information [Line Items]
Subtotal	76,983	86,667
Depreciation and amortization	(12,944)	(12,540)
Operating Segments | Consumer and Professional Products
Segment Reporting Information [Line Items]
Adjusted EBITDA	16,214	32,713
Depreciation and amortization	(8,606)	(8,199)
Operating Segments | Home and Building Products
Segment Reporting Information [Line Items]
Adjusted EBITDA	56,297	48,369
Depreciation and amortization	(4,338)	(4,341)
Segment Reconciling Items
Segment Reporting Information [Line Items]
Unallocated amounts, excluding depreciation	(12,957)	(12,629)
Net interest expense	(15,648)	(15,646)
Depreciation and amortization	(13,081)	(12,590)
Restructuring charges	(1,716)	(3,079)
Acquisition costs	$ (2,595)	$ 0