Stock-Based Compensation (Schedule of Stock-based Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Assets:
Diversified investments associated with the Executive Stock Unit Program, Current	$ 3.6	$ 3.2
Diversified investments associated with the Executive Stock Unit Program, Long-term	47.4	42.7
Diversified investments associated with the Executive Stock Unit Program, Total	51.0	45.9
Liabilities:
Share Liabilities, Current	3.5	3.2
Share Liabilities, Long-term	13.2	14.6
Other - primarily timing differences between employee withholdings and related employer contributions to be submitted to various plans' trust accounts, Current	5.6	5.9
Other - primarily timing differences between employee withholdings and related employer contributions to be submitted to various plans' trust accounts, Long-term	0.0	0.0
Other - primarily timing differences between employee withholdings and related employer contributions to be submitted to various plans' trust accounts, Total	5.6	5.9
Total liabilities associated with stock-based compensation, Current	12.7	11.4
Total liabilities associated with stock-based compensation, Long-term	51.1	45.7
Total liabilities associated with stock-based compensation, Total	63.8	57.1
Executive Stock Unit Program
Liabilities:
Share Liabilities, Current	3.6	3.2
Share Liabilities, Long-term	47.3	42.2
Share Liabilities, Total	50.9	45.4
Performance Stock Unit (TSR) award
Liabilities:
Share Liabilities, Current	0.0	1.9
Share Liabilities, Long-term	1.1	2.2
Share Liabilities, Total	1.1	4.1
Performance Stock Unit (EBIT) award
Liabilities:
Share Liabilities, Current	3.5	0.4
Share Liabilities, Long-term	2.7	1.3
Share Liabilities, Total	$ 6.2	$ 1.7