Restructuring and Restructuring Related Charges (Accrued Liability) (Details) - USD ($) $ in Millions	12 Months Ended			24 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019
Restructuring Reserve [Roll Forward]
Balance at beginning of period	$ 7.2	$ 0.8		$ 0.8
Add: Charges	8.1	7.8	$ 0.8
Less: Payments	11.1	1.4
Balance at end of period	4.2	7.2	0.8	4.2
Termination benefits
Restructuring Reserve [Roll Forward]
Balance at beginning of period	6.6	0.3		0.3
Add: Charges	4.7	7.3
Less: Payments	7.8	1.0
Balance at end of period	3.5	6.6	0.3	3.5
Contract termination costs
Restructuring Reserve [Roll Forward]
Balance at beginning of period	0.0	0.0		0.0
Add: Charges	0.4	0.0
Less: Payments	0.4	0.0
Balance at end of period	0.0	0.0	0.0	0.0
Other restructuring costs
Restructuring Reserve [Roll Forward]
Balance at beginning of period	0.6	0.5		0.5
Add: Charges	3.0	0.5
Less: Payments	2.9	0.4
Balance at end of period	$ 0.7	$ 0.6	$ 0.5	$ 0.7