Business Segment Information (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2021 USD ($) segment	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)
BUSINESS SEGMENT INFORMATION
NET SALES	$ 715,440	$ 730,471	$ 726,044
Consolidated EBIT	82,900	43,100	106,000
Less: Interest expense	(2,200)	(6,700)	(8,100)
Total income before income taxes	$ 80,671	36,406	97,877
Number of reportable segments | segment	3
Corporate, Non-Segment [Member]
BUSINESS SEGMENT INFORMATION
Consolidated EBIT	$ (42,100)	(78,400)	(41,900)
A&D
BUSINESS SEGMENT INFORMATION
NET SALES	314,824	351,876	325,700
Consolidated EBIT	56,500	69,900	70,100
USG
BUSINESS SEGMENT INFORMATION
NET SALES	202,908	191,703	211,900
Consolidated EBIT	40,900	24,400	52,200
Test
BUSINESS SEGMENT INFORMATION
NET SALES	197,708	186,892	188,400
Consolidated EBIT	$ 27,600	$ 27,200	$ 25,600