DISCONTINUED OPERATIONS - Income Statement Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	$ 53,993	$ 67,768
Income from discontinued operations before taxes	3,014	2,031
Provision (benefit) for income taxes	621	(2,039)
Defense Electronics | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	53,993	67,768
Cost of goods and services	40,961	62,101
Gross profit	13,032	5,667
Selling, general and administrative expenses	10,020	9,942
Income from discontinued operations	3,012	(4,275)
Gain on sale of business	0	6,240
Other, net	2	66
Total other income (expense)	2	6,306
Income from discontinued operations before taxes	3,014	2,031
Provision (benefit) for income taxes	621	(2,039)
Income from discontinued operations	$ 2,393	$ 4,070