Fair Value Measurements (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring Basis Financial Statement Captions [Line Items]
Long-term Debt	$ 3,878.1	$ 3,665.3
Debt Instrument, Fair Value Disclosure	4,037.3	3,535.1
Carrying amount and estimated fair value of long term debt
Long-term Debt, Carrying Amount	3,878.1	3,665.3
Long-term Debt, Fair Value	4,037.3	3,535.1
Senior Unsecured Notes Due 2028 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Financial Statement Captions [Line Items]
Long-term Debt	696.6	695.9
Debt Instrument, Fair Value Disclosure	616.8	562.3
Carrying amount and estimated fair value of long term debt
Long-term Debt, Carrying Amount	696.6	695.9
Long-term Debt, Fair Value	616.8	562.3
Senior Secured Notes Due 2026 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Financial Statement Captions [Line Items]
Long-term Debt	299.1	298.8
Debt Instrument, Fair Value Disclosure	288.0	272.8
Carrying amount and estimated fair value of long term debt
Long-term Debt, Carrying Amount	299.1	298.8
Long-term Debt, Fair Value	288.0	272.8
Secured Debt Term B [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Financial Statement Captions [Line Items]
Long-term Debt	571.0	571.7
Debt Instrument, Fair Value Disclosure	573.1	564.5
Carrying amount and estimated fair value of long term debt
Long-term Debt, Carrying Amount	571.0	571.7
Long-term Debt, Fair Value	573.1	564.5
Senior Secured Notes Due 2025
Fair Value Assets And Liabilities Measured On Recurring Basis Financial Statement Captions [Line Items]
Long-term Debt	20.8	20.7
Debt Instrument, Fair Value Disclosure	20.7	20.8
Carrying amount and estimated fair value of long term debt
Long-term Debt, Carrying Amount	20.8	20.7
Long-term Debt, Fair Value	20.7	20.8
Senior Secured Second Lien Notes Due 2025
Fair Value Assets And Liabilities Measured On Recurring Basis Financial Statement Captions [Line Items]
Long-term Debt	0.0	1,191.0
Debt Instrument, Fair Value Disclosure	0.0	1,179.0
Carrying amount and estimated fair value of long term debt
Long-term Debt, Carrying Amount	0.0	1,191.0
Long-term Debt, Fair Value	0.0	1,179.0
Senior secured first lien notes due 2029
Fair Value Assets And Liabilities Measured On Recurring Basis Financial Statement Captions [Line Items]
Long-term Debt	888.4	887.2
Debt Instrument, Fair Value Disclosure	973.0	935.7
Carrying amount and estimated fair value of long term debt
Long-term Debt, Carrying Amount	888.4	887.2
Long-term Debt, Fair Value	973.0	935.7
Exchangeable Notes Due 2028
Fair Value Assets And Liabilities Measured On Recurring Basis Financial Statement Captions [Line Items]
Long-term Debt	222.2	0.0
Debt Instrument, Fair Value Disclosure	292.6	0.0
Carrying amount and estimated fair value of long term debt
Long-term Debt, Carrying Amount	222.2	0.0
Long-term Debt, Fair Value	292.6	0.0
Senior Secured Second Lien Notes due 2030
Fair Value Assets And Liabilities Measured On Recurring Basis Financial Statement Captions [Line Items]
Long-term Debt	1,180.0	0.0
Debt Instrument, Fair Value Disclosure	1,273.1	0.0
Carrying amount and estimated fair value of long term debt
Long-term Debt, Carrying Amount	1,180.0	0.0
Long-term Debt, Fair Value	$ 1,273.1	$ 0.0