BUSINESS SEGMENTS - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 646,792	$ 632,061	$ 1,890,915	$ 1,746,849
United States
Disaggregation of Revenue [Line Items]
Revenue	490,269	498,060	1,428,109	1,376,854
Europe
Disaggregation of Revenue [Line Items]
Revenue	50,706	37,984	115,564	85,219
Canada
Disaggregation of Revenue [Line Items]
Revenue	32,990	28,972	101,922	90,171
Australia
Disaggregation of Revenue [Line Items]
Revenue	51,644	48,626	185,316	142,681
All other countries
Disaggregation of Revenue [Line Items]
Revenue	21,183	18,419	60,004	51,924
Consumer and Professional Products
Disaggregation of Revenue [Line Items]
Revenue	324,826	328,929	947,739	844,917
Consumer and Professional Products | United States
Disaggregation of Revenue [Line Items]
Revenue	206,809	232,544	595,619	584,114
Consumer and Professional Products | Europe
Disaggregation of Revenue [Line Items]
Revenue	43,767	29,267	95,888	60,609
Consumer and Professional Products | Canada
Disaggregation of Revenue [Line Items]
Revenue	20,547	18,231	64,440	53,527
Consumer and Professional Products | Australia
Disaggregation of Revenue [Line Items]
Revenue	51,437	47,614	184,668	140,874
Consumer and Professional Products | All other countries
Disaggregation of Revenue [Line Items]
Revenue	2,266	1,273	7,124	5,793
Consumer and Professional Products | Residential repair and remodel
Disaggregation of Revenue [Line Items]
Revenue	50,165	50,709	146,325	126,304
Consumer and Professional Products | Retail
Disaggregation of Revenue [Line Items]
Revenue	154,212	177,271	447,206	441,795
Consumer and Professional Products | Residential new construction
Disaggregation of Revenue [Line Items]
Revenue	12,147	14,487	40,202	44,344
Consumer and Professional Products | Industrial
Disaggregation of Revenue [Line Items]
Revenue	12,708	9,303	32,197	30,461
Consumer and Professional Products | International excluding North America
Disaggregation of Revenue [Line Items]
Revenue	95,594	77,159	281,809	202,013
Home and Building Products
Disaggregation of Revenue [Line Items]
Revenue	259,392	219,164	752,684	670,374
Home and Building Products | United States
Disaggregation of Revenue [Line Items]
Revenue	246,268	209,222	713,754	635,232
Home and Building Products | Europe
Disaggregation of Revenue [Line Items]
Revenue	31	81	72	109
Home and Building Products | Canada
Disaggregation of Revenue [Line Items]
Revenue	10,724	7,729	32,009	26,849
Home and Building Products | Australia
Disaggregation of Revenue [Line Items]
Revenue	0	0	0	0
Home and Building Products | All other countries
Disaggregation of Revenue [Line Items]
Revenue	2,369	2,132	6,849	8,184
Home and Building Products | Residential repair and remodel
Disaggregation of Revenue [Line Items]
Revenue	127,827	109,876	374,769	332,681
Home and Building Products | Residential new construction
Disaggregation of Revenue [Line Items]
Revenue	28,811	24,767	84,471	74,985
Home and Building Products | Commercial construction
Disaggregation of Revenue [Line Items]
Revenue	102,754	84,521	293,444	262,708
Defense Electronics
Disaggregation of Revenue [Line Items]
Revenue	62,574	83,968	190,492	231,558
Defense Electronics | United States
Disaggregation of Revenue [Line Items]
Revenue	37,192	56,294	118,736	157,508
Defense Electronics | Europe
Disaggregation of Revenue [Line Items]
Revenue	6,908	8,636	19,604	24,501
Defense Electronics | Canada
Disaggregation of Revenue [Line Items]
Revenue	1,719	3,012	5,473	9,795
Defense Electronics | Australia
Disaggregation of Revenue [Line Items]
Revenue	207	1,012	648	1,807
Defense Electronics | All other countries
Disaggregation of Revenue [Line Items]
Revenue	16,548	15,014	46,031	37,947
Defense Electronics | U.S. Government
Disaggregation of Revenue [Line Items]
Revenue	45,275	54,802	127,644	151,126
Defense Electronics | International
Disaggregation of Revenue [Line Items]
Revenue	15,141	24,779	53,533	68,333
Defense Electronics | Commercial
Disaggregation of Revenue [Line Items]
Revenue	$ 2,158	$ 4,387	$ 9,315	$ 12,099