GOODWILL AND OTHER INTANGIBLE ASSETS - Changes in carrying amount of goodwill (Details) $ in Thousands	6 Months Ended
	Mar. 31, 2024 USD ($)
GOODWILL AND OTHER INTANGIBLE ASSETS
Beginning Balance	$ 503,177
Acquisition activity	30,300
Foreign currency translation	2,200
Ending Balance	535,661
USG
GOODWILL AND OTHER INTANGIBLE ASSETS
Beginning Balance	353,600
Foreign currency translation	1,400
Ending Balance	355,000
Test
GOODWILL AND OTHER INTANGIBLE ASSETS
Beginning Balance	34,000
Acquisition activity	30,300
Foreign currency translation	800
Ending Balance	65,100
A&D
GOODWILL AND OTHER INTANGIBLE ASSETS
Beginning Balance	115,600
Ending Balance	$ 115,600