Fair Value Measurements and Derivative Instruments - Summary of Effects on Consolidated Financial Statements of Designated As Cash Flow Hedges (Details) - Cash Flow Hedges - Designated - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Interest Rate Swaps
Derivative Instruments Gain Loss [Line Items]
Derivative Instrument, Gain (Loss) Reclassified from AOCI into Income, Effective Portion, Statement of Income or Comprehensive Income [Extensible Enumeration]	Interest Expense	Interest Expense
Income recognized in Other comprehensive (loss) income	$ 0.0	$ 1.1
Net income (loss) reclassified from Accumulated other comprehensive Income (loss) into Interest expense/Cost of services provided	$ 3.0	$ (0.8)
Fuel Swap Contracts
Derivative Instruments Gain Loss [Line Items]
Derivative Instrument, Gain (Loss) Reclassified from AOCI into Income, Effective Portion, Statement of Income or Comprehensive Income [Extensible Enumeration]	Cost of Goods and Services Sold	Cost of Goods and Services Sold
Income recognized in Other comprehensive (loss) income	$ 0.0	$ 0.2
Net income (loss) reclassified from Accumulated other comprehensive Income (loss) into Interest expense/Cost of services provided	$ 0.0	$ 1.5