GOODWILL AND OTHER INTANGIBLE ASSETS - Changes in carrying amount of goodwill (Details) $ in Thousands	9 Months Ended
	Jun. 30, 2023 USD ($)
GOODWILL AND OTHER INTANGIBLE ASSETS
Beginning Balance	$ 492,709
Acquisition activity and adjustments	5,600
Foreign currency translation	7,300
Ending Balance	505,590
USG
GOODWILL AND OTHER INTANGIBLE ASSETS
Beginning Balance	348,700
Foreign currency translation	7,300
Ending Balance	356,000
Test
GOODWILL AND OTHER INTANGIBLE ASSETS
Beginning Balance	34,000
Ending Balance	34,000
Aerospace & Defense
GOODWILL AND OTHER INTANGIBLE ASSETS
Beginning Balance	110,000
Acquisition activity and adjustments	5,600
Ending Balance	$ 115,600