Stock-Based Compensation (Schedule of Stock-based Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Assets:
Diversified investments associated with the Executive Stock Unit Program, Current	$ 2.8	$ 2.3
Diversified investments associated with the Executive Stock Unit Program, Long-term	38.2	30.4
Diversified investments associated with the Executive Stock Unit Program, Total	41.0	32.7
Liabilities:
Share Liabilities, Current	2.8	2.3
Share Liabilities, Long-term	14.6	17.6
Other - primarily timing differences between employee withholdings and related employer contributions to be submitted to various plans' trust accounts, Current	6.2	7.4
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	6.2	7.4
Total liabilities associated with stock-based compensation, Current	14.6	14.6
Total liabilities associated with stock-based compensation, Long-term	46.5	34.6
Total liabilities associated with stock-based compensation, Total	61.1	49.2
Executive Stock Unit Program
Liabilities:
Share Liabilities, Current	2.8	2.3
Share Liabilities, Long-term	37.8	31.4
Share Liabilities, Total	40.6	33.7
Performance Stock Unit (TSR) award
Liabilities:
Share Liabilities, Current	1.5	0.6
Share Liabilities, Long-term	5.0	0.7
Share Liabilities, Total	6.5	1.3
Performance Stock Unit (EBIT) award
Liabilities:
Share Liabilities, Current	4.1	0.0
Share Liabilities, Long-term	3.7	2.5
Share Liabilities, Total	7.8	2.5
Profitable Growth Incentive award
Liabilities:
Share Liabilities, Current	0.0	4.3
Share Liabilities, Long-term	0.0	0.0
Share Liabilities, Total	$ 0.0	$ 4.3