BUSINESS SEGMENTS - Summary of Segment Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Continuing assets	$ 2,315,553	$ 2,071,730
Assets of discontinued operations	3,194	3,209
Total Assets	2,318,747	2,074,939
Operating Segments
Segment Reporting Information [Line Items]
Continuing assets	2,219,468	1,989,301
Operating Segments | Consumer and Professional Products
Segment Reporting Information [Line Items]
Continuing assets	1,279,376	1,070,510
Operating Segments | Home and Building Products
Segment Reporting Information [Line Items]
Continuing assets	592,011	571,216
Operating Segments | Defense Electronics
Segment Reporting Information [Line Items]
Continuing assets	348,081	347,575
Corporate
Segment Reporting Information [Line Items]
Continuing assets	$ 96,085	$ 82,429