Contingencies - Litigation and Other Matters (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Sep. 30, 2023
Loss Contingencies [Line Items]
Accrued amounts for litigation and other contingent liabilities	$ 8,775	$ 9,404
Performance Bonds
Loss Contingencies [Line Items]
Letters of credit secured using cash collateral	34,800
Outstanding performance bonds	$ 255,400