Derivative Financial Instruments and Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023	Jun. 30, 2022	Sep. 30, 2021
Derivative [Line Items]
Gain recorded representing decrease in fair value	$ 2.5	$ 7.2
Interest Rate Swap | Cash Flow Hedging | Designated as Hedging Instrument
Derivative [Line Items]
Notional value					$ 400.0
Fixed interest rate (as percent)					1.283%
Material losses recognized in income	0.0	0.0	$ 0.0
Interest Rate Cap | Cash Flow Hedging | Designated as Hedging Instrument
Derivative [Line Items]
Notional value				$ 300.0
Fixed interest rate (as percent)				3.465%
Derivative, basis spread on variable rate (as percent)				3.465%
FY 2025 Fourth Quarter Acquisition
Derivative [Line Items]
Maximum value of contingent consideration issued	17.7
February 2023 | United States of America, Dollars | Interest Rate Swap | Cash Flow Hedging | Designated as Hedging Instrument
Derivative [Line Items]
Notional value	$ 400.0	$ 400.0
Fixed interest rate (as percent)	1.283%	1.283%