Commitments and Contingencies (Pace and Pasadena Narrative) (Details) $ in Millions	12 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2012 USD ($) surfaceImpoundmentUnit	Sep. 30, 2006 USD ($)
Loss Contingencies [Line Items]
Pretax environmental expense	$ 27.0	$ 24.9	$ 22.3
Pre-tax loss from discontinued operations	19.4
Environmental
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies	$ 79.1	$ 64.5
Accrual for environmental loss contingencies, maximum payout period	30 years
Pace, Florida
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies	$ 54.7				$ 42.0
Change in estimated exposure	19.4
Pace, Florida | Discontinued Operations
Loss Contingencies [Line Items]
Pretax environmental expense					$ 42.0
Pasadena, Texas
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies	$ 10.3
Total anticipated exposure				$ 13.0
Number Of Closed Facilities | surfaceImpoundmentUnit				2