Goodwill and Intangible Assets - Components of Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Sep. 30, 2023
Finite-Lived Intangible Assets [Line Items]
Cost	$ 519,227	$ 515,636
Accumulated Amortization	251,601	221,335
Net Book Value	267,626	294,301
Patents
Finite-Lived Intangible Assets [Line Items]
Cost	1,226	1,226
Accumulated Amortization	1,185	1,175
Net Book Value	41	51
Completed Technology
Finite-Lived Intangible Assets [Line Items]
Cost	225,235	215,430
Accumulated Amortization	74,969	56,021
Net Book Value	150,266	159,409
Trademarks and Trade Names
Finite-Lived Intangible Assets [Line Items]
Cost	6,763	6,630
Accumulated Amortization	2,250	1,445
Net Book Value	4,513	5,185
Non-competition agreements
Finite-Lived Intangible Assets [Line Items]
Cost		681
Accumulated Amortization		568
Net Book Value		113
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Cost	285,116	290,800
Accumulated Amortization	172,310	161,257
Net Book Value	112,806	129,543
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Cost	887	869
Accumulated Amortization	$ 887	$ 869