Fair Value Measurement (Fair Value Assets and Liabilities) (Details) - Fair Value, Recurring - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Carrying amount | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans receivable	$ 41.4	$ 37.7
Derivative financial assets	0.1	0.4
Fair value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans receivable	41.3	37.6
Derivative financial assets	0.1	0.4
Secured Debt | 2023 Secured Notes | Carrying amount | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	543.6	543.2
Secured Debt | 2023 Secured Notes | Fair value | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	560.0	565.1
Unsecured Debt | 2023 Unsecured Notes | Carrying amount | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	789.8	789.5
Unsecured Debt | 2023 Unsecured Notes | Fair value | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	837.0	848.0
Term Loans | Carrying amount | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	1,592.8	1,743.1
Term Loans | Fair value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	$ 1,605.1	$ 1,758.1