GOODWILL AND OTHER INTANGIBLE ASSETS - Intangible assets gross carrying amounts and accumulated amortization (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Sep. 30, 2023
GOODWILL AND OTHER INTANGIBLE ASSETS
Goodwill	$ 535,661	$ 503,177
Less: accumulated amortization	221,321	204,881
Trade names
GOODWILL AND OTHER INTANGIBLE ASSETS
Trade names	162,796	161,447
Customer Relationships
GOODWILL AND OTHER INTANGIBLE ASSETS
Gross carrying amount	327,695	296,927
Less: accumulated amortization	122,542	113,311
Net	205,153	183,616
Capitalized software
GOODWILL AND OTHER INTANGIBLE ASSETS
Gross carrying amount	128,042	121,883
Less: accumulated amortization	86,622	80,774
Net	41,420	41,109
Patents
GOODWILL AND OTHER INTANGIBLE ASSETS
Gross carrying amount	2,516	2,516
Less: accumulated amortization	1,287	1,218
Net	1,229	1,298
Other
GOODWILL AND OTHER INTANGIBLE ASSETS
Gross carrying amount	15,144	14,232
Less: accumulated amortization	10,870	9,578
Net	$ 4,274	$ 4,654