BUSINESS SEGMENTS - Summary of Segment Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Continuing assets	$ 2,302,183	$ 2,071,730
Assets of discontinued operations	8,037	3,209
Total Assets	2,310,220	2,074,939
Operating Segments
Segment Reporting Information [Line Items]
Continuing assets	2,196,840	1,989,301
Operating Segments | Consumer and Professional Products
Segment Reporting Information [Line Items]
Continuing assets	1,269,540	1,070,510
Operating Segments | Home and Building Products
Segment Reporting Information [Line Items]
Continuing assets	592,038	571,216
Operating Segments | Defense Electronics
Segment Reporting Information [Line Items]
Continuing assets	335,262	347,575
Corporate
Segment Reporting Information [Line Items]
Continuing assets	$ 105,343	$ 82,429