Commitments and Contingencies (Litigation and Environmental - Narrative) (Details) - Environmental $ in Millions	Mar. 31, 2026 USD ($) site	Sep. 30, 2025 USD ($)
Loss Contingencies [Line Items]
Approximate number of sites on which settlement has not been reached | site	26
Accrual for environmental loss contingencies	$ 83.9	$ 85.6
Accrual for environmental loss contingencies, maximum payout period	30 years
Minimum
Loss Contingencies [Line Items]
Estimate of possible exposure from environmental loss contingencies	$ 83.0
Maximum
Loss Contingencies [Line Items]
Estimate of possible exposure from environmental loss contingencies	$ 97.0