GOODWILL AND OTHER INTANGIBLE ASSETS - Intangible assets gross carrying amounts and accumulated amortization (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023
GOODWILL AND OTHER INTANGIBLE ASSETS
Goodwill	$ 537,601	$ 503,177
Less: accumulated amortization	212,750	204,881
Trade names
GOODWILL AND OTHER INTANGIBLE ASSETS
Trade names	163,209	161,447
Customer Relationships
GOODWILL AND OTHER INTANGIBLE ASSETS
Gross carrying amount	328,624	296,927
Less: accumulated amortization	117,755	113,311
Net	210,869	183,616
Capitalized software
GOODWILL AND OTHER INTANGIBLE ASSETS
Gross carrying amount	125,237	121,883
Less: accumulated amortization	83,709	80,774
Net	41,528	41,109
Patents
GOODWILL AND OTHER INTANGIBLE ASSETS
Gross carrying amount	2,517	2,516
Less: accumulated amortization	1,253	1,218
Net	1,264	1,298
Other
GOODWILL AND OTHER INTANGIBLE ASSETS
Gross carrying amount	15,216	14,232
Less: accumulated amortization	10,033	9,578
Net	$ 5,183	$ 4,654