Debt (Summary of Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Mar. 15, 2023	Dec. 31, 2022	Dec. 21, 2016
Debt [Line Items]
Short-term debt	$ 13.7		$ 29.1
Total long-term debt	3,075.8		581.5
Total debt	3,089.5		610.6
Current portion	14.2		4.4
Non-current portion	3,061.6		577.1
Term loans
Debt [Line Items]
Less: unamortized debt issuance costs	$ (15.0)		(0.4)
DDTL Facility loan denominated in Canadian dollars, secured | Term loans
Debt [Line Items]
Weighted average interest rate	5.86%
Long-term debt:	$ 0.0		85.5
CAD TLA Facility | Term loans
Debt [Line Items]
Weighted average interest rate	7.90%
Long-term debt:	$ 83.1		0.0
USD TLA Facility | Term loans
Debt [Line Items]
Weighted average interest rate	7.95%
Long-term debt:	$ 1,675.0		0.0
5.375% Senior unsecured notes due in January 2025 (the "2016 Notes") | Unsecured Debt
Debt [Line Items]
Interest rate				5.375%
Long-term debt:	0.0		500.0
Less: unamortized debt issuance costs	0.0		(3.6)
6.750% Senior secured notes due in March 2028 (the "2023 Secured Notes") | Secured Debt
Debt [Line Items]
Interest rate		6.75%
Long-term debt:	550.0		0.0
Less: unamortized debt issuance costs	(6.8)		0.0
7.750% Senior unsecured notes due in March 2031 (the "2023 Unsecured Notes") | Unsecured Debt
Debt [Line Items]
Interest rate		7.75%
Long-term debt:	800.0		0.0
Less: unamortized debt issuance costs	$ (10.5)		$ 0.0