Commitments and Contingencies (Litigation and Environmental - Narrative) (Details) R$ in Millions	1 Months Ended	6 Months Ended
	Sep. 30, 2010 BRL (R$)	Mar. 31, 2025 USD ($)	Mar. 31, 2025 BRL (R$) site	Mar. 31, 2025 USD ($) site	Sep. 30, 2024 USD ($)
Alleged Anticompete Litigation
Loss Contingencies [Line Items]
Civil fines imposed	R$ 179.2	$ 31,000,000
Provision for litigation		$ 0
Maximum of loss contingency range subject to interest			R$ 179.2	$ 31,000,000
Environmental
Loss Contingencies [Line Items]
Approximate number of sites on which settlement has not been reached | site			25	25
Accrual for environmental loss contingencies				$ 79,300,000	$ 79,100,000
Accrual for environmental loss contingencies, maximum payout period			30 years	30 years
Environmental | Minimum
Loss Contingencies [Line Items]
Estimate of possible exposure from environmental loss contingencies				$ 79,000,000
Environmental | Maximum
Loss Contingencies [Line Items]
Estimate of possible exposure from environmental loss contingencies				$ 92,000,000