Restructuring (Restructuring Liability) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Utilization	$ (32.3)	$ (17.5)	$ (7.2)
2020 Repositioning Actions
Restructuring Cost and Reserve [Line Items]
Utilization	(32.1)	0.0	0.0
2019 Repositioning Actions
Restructuring Cost and Reserve [Line Items]
Utilization	(6.1)	(9.9)	0.0
2017 Repositioning Actions
Restructuring Cost and Reserve [Line Items]
Utilization	6.2	(2.3)	(5.6)
Acquisition-Related Restructuring
Restructuring Cost and Reserve [Line Items]
Utilization	0.0	(5.3)	(1.6)
Severance
Restructuring Cost and Reserve [Line Items]
Beginning balance	22.4	23.2
Expense (Gain)	27.8	12.5
Adjustment	1.4
Utilization	(26.7)	(13.3)
Ending balance	24.9	22.4	23.2
Severance | 2020 Repositioning Actions
Restructuring Cost and Reserve [Line Items]
Beginning balance	0.0	0.0
Expense (Gain)	27.5	0.0
Adjustment	0.0
Utilization	(23.3)	0.0
Ending balance	4.2	0.0	0.0
Severance | 2019 Repositioning Actions
Restructuring Cost and Reserve [Line Items]
Beginning balance	9.9	0.0
Expense (Gain)	0.0	9.9
Adjustment	6.1
Utilization	0.0	0.0
Ending balance	16.0	9.9	0.0
Severance | 2017 Repositioning Actions
Restructuring Cost and Reserve [Line Items]
Beginning balance	12.5	23.2
Expense (Gain)	0.0	0.9
Adjustment	(4.7)
Utilization	(3.1)	(11.6)
Ending balance	4.7	12.5	23.2
Severance | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Beginning balance	0.0	0.0
Expense (Gain)	0.0	1.7
Adjustment	0.0
Utilization	0.0	(1.7)
Ending balance	0.0	0.0	0.0
Severance | Acquisition-Related Restructuring
Restructuring Cost and Reserve [Line Items]
Beginning balance	0.0	0.0
Expense (Gain)	0.3	0.0
Adjustment	0.0
Utilization	(0.3)	0.0
Ending balance	0.0	0.0	0.0
Other Restructuring Costs
Restructuring Cost and Reserve [Line Items]
Beginning balance	0.2	0.0
Expense (Gain)	3.1	5.0
Utilization	(3.3)	(4.8)
Ending balance	0.0	0.2	0.0
Other Restructuring Costs | 2020 Repositioning Actions
Restructuring Cost and Reserve [Line Items]
Beginning balance	0.0	0.0
Expense (Gain)	4.6	0.0
Utilization	(4.6)	0.0
Ending balance	0.0	0.0	0.0
Other Restructuring Costs | 2019 Repositioning Actions
Restructuring Cost and Reserve [Line Items]
Beginning balance	0.0	0.0
Expense (Gain)	0.0	0.0
Utilization	0.0	0.0
Ending balance	0.0	0.0	0.0
Other Restructuring Costs | 2017 Repositioning Actions
Restructuring Cost and Reserve [Line Items]
Beginning balance	0.2	0.0
Expense (Gain)	(1.5)	1.4
Utilization	1.3	(1.2)
Ending balance	0.0	0.2	0.0
Other Restructuring Costs | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Beginning balance	0.0	0.0
Expense (Gain)	0.0	3.6
Utilization	0.0	(3.6)
Ending balance	0.0	0.0	0.0
Other Restructuring Costs | Acquisition-Related Restructuring
Restructuring Cost and Reserve [Line Items]
Beginning balance	0.0	0.0
Expense (Gain)	0.0	0.0
Utilization	0.0	0.0
Ending balance	$ 0.0	$ 0.0	$ 0.0