Contingencies - Litigation and Other Matters (Details) - USD ($) $ in Millions	Jun. 30, 2023	Sep. 30, 2022
Loss Contingencies [Line Items]
Accrued amounts for litigation and other contingent liabilities	$ 8.2	$ 9.8
Performance Bonds
Loss Contingencies [Line Items]
Letters of credit secured using cash collateral	32.1
Outstanding performance bonds	$ 283.6