BUSINESS SEGMENTS - Revenues (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) segment	Jun. 30, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			3
Revenue	$ 646,792	$ 632,061	$ 1,890,915	$ 1,746,849
Consumer and Professional Products
Segment Reporting Information [Line Items]
Revenue	324,826	328,929	947,739	844,917
Home and Building Products
Segment Reporting Information [Line Items]
Revenue	259,392	219,164	752,684	670,374
Defense Electronics
Segment Reporting Information [Line Items]
Revenue	$ 62,574	$ 83,968	$ 190,492	$ 231,558