BUSINESS SEGMENTS - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 609,291	$ 548,438
United States
Disaggregation of Revenue [Line Items]
Revenue	467,351	433,251
Europe
Disaggregation of Revenue [Line Items]
Revenue	20,061	12,613
Canada
Disaggregation of Revenue [Line Items]
Revenue	35,432	31,608
Australia
Disaggregation of Revenue [Line Items]
Revenue	69,859	54,834
All other countries
Disaggregation of Revenue [Line Items]
Revenue	16,588	16,132
Consumer and Professional Products
Disaggregation of Revenue [Line Items]
Revenue	291,042	241,076
Consumer and Professional Products | United States
Disaggregation of Revenue [Line Items]
Revenue	183,442	160,158
Consumer and Professional Products | Europe
Disaggregation of Revenue [Line Items]
Revenue	13,156	6,605
Consumer and Professional Products | Canada
Disaggregation of Revenue [Line Items]
Revenue	22,115	17,781
Consumer and Professional Products | Australia
Disaggregation of Revenue [Line Items]
Revenue	69,540	54,228
Consumer and Professional Products | All other countries
Disaggregation of Revenue [Line Items]
Revenue	2,789	2,304
Consumer and Professional Products | Residential repair and remodel
Disaggregation of Revenue [Line Items]
Revenue	45,600	35,090
Consumer and Professional Products | Retail
Disaggregation of Revenue [Line Items]
Revenue	139,248	119,620
Consumer and Professional Products | Residential new construction
Disaggregation of Revenue [Line Items]
Revenue	13,515	14,973
Consumer and Professional Products | Industrial
Disaggregation of Revenue [Line Items]
Revenue	9,531	10,623
Consumer and Professional Products | International excluding North America
Disaggregation of Revenue [Line Items]
Revenue	83,148	60,770
Home and Building Products
Disaggregation of Revenue [Line Items]
Revenue	250,481	241,381
Home and Building Products | United States
Disaggregation of Revenue [Line Items]
Revenue	236,531	226,950
Home and Building Products | Europe
Disaggregation of Revenue [Line Items]
Revenue	0	23
Home and Building Products | Canada
Disaggregation of Revenue [Line Items]
Revenue	11,488	11,253
Home and Building Products | Australia
Disaggregation of Revenue [Line Items]
Revenue	0	0
Home and Building Products | All other countries
Disaggregation of Revenue [Line Items]
Revenue	2,462	3,155
Home and Building Products | Residential repair and remodel
Disaggregation of Revenue [Line Items]
Revenue	126,115	121,997
Home and Building Products | Residential new construction
Disaggregation of Revenue [Line Items]
Revenue	28,427	27,497
Home and Building Products | Commercial construction
Disaggregation of Revenue [Line Items]
Revenue	95,939	91,887
Defense Electronics
Disaggregation of Revenue [Line Items]
Revenue	67,768	65,981
Defense Electronics | United States
Disaggregation of Revenue [Line Items]
Revenue	47,378	46,143
Defense Electronics | Europe
Disaggregation of Revenue [Line Items]
Revenue	6,905	5,985
Defense Electronics | Canada
Disaggregation of Revenue [Line Items]
Revenue	1,829	2,574
Defense Electronics | Australia
Disaggregation of Revenue [Line Items]
Revenue	319	606
Defense Electronics | All other countries
Disaggregation of Revenue [Line Items]
Revenue	11,337	10,673
Defense Electronics | U.S. Government
Disaggregation of Revenue [Line Items]
Revenue	47,324	42,701
Defense Electronics | International
Disaggregation of Revenue [Line Items]
Revenue	16,895	18,533
Defense Electronics | Commercial
Disaggregation of Revenue [Line Items]
Revenue	$ 3,549	$ 4,747