Capital Stock and Equity Compensation (Schedule of Equity Compensation Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Compensation expense	$ 15.1	$ 14.3	$ 11.8
Performance-based restricted stock units
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Compensation expense	6.0	3.7	2.3
Time-based restricted stock units
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Compensation expense	7.3	9.2	8.2
Deferred stock units
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Compensation expense	1.3	1.3	1.3
Other
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Compensation expense	$ 0.5	$ 0.1	$ 0.0