Debt (Summary of Debt) (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023	Mar. 15, 2023
Debt [Line Items]
Short-term debt	$ 29.9	$ 13.7
Total long-term debt	2,826.9	3,075.8
Total debt	2,856.8	3,089.5
Current portion	4.3	14.2
Non-current portion	2,822.6	3,061.6
Term Loans
Debt [Line Items]
Less: unamortized debt issuance costs	$ (10.5)	(15.0)
CAD TLA Facility | Term Loans
Debt [Line Items]
Weighted average interest rate	7.63%
Long-term debt:	$ 78.2	83.1
USD TLA Facility | Term Loans
Debt [Line Items]
Weighted average interest rate	7.78%
Long-term debt:	$ 1,425.0	1,675.0
6.75% Senior secured notes due in March 2028 (the "Secured Notes") | Secured Debt
Debt [Line Items]
Interest rate	6.75%		6.75%
Long-term debt:	$ 550.0	550.0
Less: unamortized debt issuance costs	$ (6.0)	(6.8)
7.75% Senior unsecured notes due in March 2031 (the "Unsecured Notes") | Unsecured Debt
Debt [Line Items]
Interest rate	7.75%		7.75%
Long-term debt:	$ 800.0	800.0
Less: unamortized debt issuance costs	$ (9.8)	$ (10.5)