REPORTABLE SEGMENTS - Disaggregation of revenue by segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Revenue	$ 2,270,626	$ 2,066,546	$ 1,874,248
Revenue from Defense Electronics	271,060	340,976	335,041
Subtotal	2,541,686	2,407,522	2,209,289
Discontinued Operations, Held-for-sale | Defense Electronics
Segment Reporting Information [Line Items]
Revenue from Defense Electronics	271,060	340,976	335,041
Consumer and Professional Products
Segment Reporting Information [Line Items]
Revenue	1,229,518	1,139,233	1,000,608
Home and Building Products
Segment Reporting Information [Line Items]
Revenue	$ 1,041,108	$ 927,313	$ 873,640