Capital Stock and Equity Compensation (Schedule of Equity Compensation Expense) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total equity compensation expense	$ 4.3	$ 5.3	$ 7.9	$ 8.8
Performance-Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total equity compensation expense	2.1	2.0	3.9	3.3
Time-Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total equity compensation expense	1.8	2.1	3.5	4.0
Deferred Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total equity compensation expense	0.1	1.3	0.2	1.3
Other
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total equity compensation expense	$ 0.3	$ (0.1)	$ 0.3	$ 0.2