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		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Interest Rate 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]	Interest Income (Expense), Net	Interest Income (Expense), Net	Interest Income (Expense), Net	Interest Income (Expense), Net
Income (Loss) recognized in Other comprehensive income (loss)	$ 10.9	$ 1.5	$ (3.6)	$ 1.5
Net income reclassified from Accumulated other comprehensive income into Interest expense	$ 2.8	$ 1.3	$ 5.6	$ 4.3
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	Cost of Goods and Services Sold	Cost of Goods and Services Sold
Income (Loss) recognized in Other comprehensive income (loss)	$ 0.1	$ 0.0	$ 0.1	$ 0.0
Net income reclassified from Accumulated other comprehensive income into Interest expense	$ 0.0	$ 0.0	$ 0.0	$ 0.0