DISCONTINUED OPERATIONS - Income Statement Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from discontinued operations before taxes	$ 694	$ (1,341)	$ 3,708	$ 690
Provision (benefit) for income taxes	(6,424)	(334)	(5,803)	(2,373)
Defense Electronics | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	56,273	60,150	110,266	127,918
Cost of goods and services	45,188	51,411	86,149	113,512
Gross profit	11,085	8,739	24,117	14,406
Selling, general and administrative expenses	10,289	9,359	20,309	19,301
Income from discontinued operations	796	(620)	3,808	(4,895)
Interest income, net	2	1	2	1
Gain on sale of business	0	(949)	0	5,291
Other, net	(104)	227	(102)	293
Total other income (expense)	(102)	(721)	(100)	5,585
Income from discontinued operations before taxes	694	(1,341)	3,708	690
Provision (benefit) for income taxes	(6,424)	(334)	(5,803)	(2,373)
Income from discontinued operations	$ 7,118	$ (1,007)	$ 9,511	$ 3,063