Goodwill and Other Intangible Assets - Intangible assets gross carrying amounts and accumulated amortization (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Goodwill and Other Intangible Assets
Goodwill	$ 503,177	$ 492,709	$ 504,900
Trade names
Goodwill and Other Intangible Assets
Trade names	161,447	160,024
Patents
Goodwill and Other Intangible Assets
Gross carrying amount	2,516	2,353
Less: accumulated amortization	1,218	1,091
Net	1,298	1,262
Capitalized software
Goodwill and Other Intangible Assets
Gross carrying amount	121,883	106,583
Less: accumulated amortization	80,774	70,476
Net	41,109	36,107
Customer Relationships
Goodwill and Other Intangible Assets
Gross carrying amount	296,927	287,447
Less: accumulated amortization	113,311	96,921
Net	183,616	190,526
Other
Goodwill and Other Intangible Assets
Gross carrying amount	14,232	13,985
Less: accumulated amortization	9,578	7,440
Net	$ 4,654	$ 6,545