DISCONTINUED OPERATIONS - Income statement information (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from discontinued operations before tax	$ 116,345	$ 10,121	$ 15,276
Provision for income taxes	20,188	1,212	3,291
Defense Electronics | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	161,061	271,060	340,976
Cost of goods and services	125,208	232,075	285,022
Gross profit	35,853	38,985	55,954
Selling, general and administrative expenses	26,423	35,532	42,314
Income from discontinued operations	9,430	3,453	13,640
Gain on sale of business	107,517	5,291	0
Interest income, net	2	117	4
Other, net	(604)	1,260	1,632
Total other income (expense)	106,915	6,668	1,636
Income from discontinued operations before tax	116,345	10,121	15,276
Provision for income taxes	20,188	1,212	3,291
Income from discontinued operations	$ 96,157	$ 8,909	$ 11,985