Financial Instruments and Fair Value - Schedule of Assets and Liabilities Measured at Fair Value Recurring Basis (Details) $ in Millions	Sep. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)	Jun. 30, 2023 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments			$ 2.0
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other assets (includes $14.1 and $31.3 at fair value)	Other assets (includes $14.1 and $31.3 at fair value)
Measurement Input, Risk Free Interest Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		$ 735.5
Minimum | Measurement Input, Risk Free Interest Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.038
Maximum | Measurement Input, Risk Free Interest Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.056
Level 1 | Measurement Input, Risk Free Interest Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		650.7
Level 2 | Measurement Input, Risk Free Interest Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		76.3
Level 3 | Measurement Input, Risk Free Interest Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		8.5
Recurring fair value measurements:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	$ 9.4	22.8
Debt securities	4.7	4.7
Other investments	0.0	3.8
Total assets	916.7
Recurring fair value measurements: | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	0.0	0.0
Debt securities	0.0	0.0
Other investments	0.0	0.0
Total assets	795.6
Recurring fair value measurements: | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	9.4	22.8
Debt securities	0.0	0.0
Other investments	0.0	0.0
Total assets	116.4
Recurring fair value measurements: | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	0.0	0.0
Debt securities	4.7	4.7
Other investments	0.0	3.8
Total assets	4.7
Cash | Recurring fair value measurements:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	109.1	103.7
Cash | Recurring fair value measurements: | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	109.1	103.7
Cash | Recurring fair value measurements: | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	0.0	0.0
Cash | Recurring fair value measurements: | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	0.0	0.0
Money market mutual funds | Recurring fair value measurements:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	686.5	547.0
Money market mutual funds | Recurring fair value measurements: | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	686.5	547.0
Money market mutual funds | Recurring fair value measurements: | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	0.0	0.0
Money market mutual funds | Recurring fair value measurements: | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	0.0	0.0
Term deposits | Recurring fair value measurements:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	107.0	53.5
Term deposits | Recurring fair value measurements: | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	0.0	0.0
Term deposits | Recurring fair value measurements: | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	107.0	53.5
Term deposits | Recurring fair value measurements: | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	$ 0.0	$ 0.0