REPORTABLE SEGMENTS - Schedule of disaggregated 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
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
Residential Repair and Remodel | Consumer and Professional Products
Segment Reporting Information [Line Items]
Revenue	185,896	173,859	140,369
Residential Repair and Remodel | Home and Building Products
Segment Reporting Information [Line Items]
Revenue	516,995	467,112	439,287
Retail | Consumer and Professional Products
Segment Reporting Information [Line Items]
Revenue	577,839	575,947	528,279
Residential New Construction | Consumer and Professional Products
Segment Reporting Information [Line Items]
Revenue	50,437	59,907	58,709
Residential New Construction | Home and Building Products
Segment Reporting Information [Line Items]
Revenue	116,528	105,285	99,014
Industrial | Consumer and Professional Products
Segment Reporting Information [Line Items]
Revenue	43,411	40,285	45,129
International Excluding North America | Consumer and Professional Products
Segment Reporting Information [Line Items]
Revenue	371,935	289,235	228,122
Commercial Construction | Home and Building Products
Segment Reporting Information [Line Items]
Revenue	$ 407,585	$ 354,916	$ 335,339