Restructuring (Narrative) (Details) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Restructuring Cost and Reserve [Line Items]
Other Costs related to repositioning actions			$ 2.3
Restructuring and Related Cost, Expected Cost Remaining	$ 16.7		16.7
Restructuring and Related Cost, Expected Number of Positions Eliminated					300
Restructuring and Related Cost, Number of Positions Eliminated, Period Percent					3.00%
Restructuring Charges	$ (0.6)	$ 0.0	0.2	$ 0.0
Severance Costs			0.3
Other Restructuring Costs			(0.1)
Effect on Future Earnings, Amount					$ 30.0
cumulative [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			24.3
Severance Costs			24.4
Other Restructuring Costs			$ (0.1)