Restructuring (Narrative) (Details) $ in Millions	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2017 employee	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($) employee
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 1.6	$ (0.6)		$ 4.5	$ 0.2	$ 7.2
Acquisition-Related Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0.6			2.8		$ 1.6
Restructuring and related cost, expected number of positions eliminated | employee						170
Restructuring and related cost, number of positions eliminated, period percent						2.00%
Severance costs	0.2			0.4
Other restructuring costs	0.4			2.4
Other costs related to repositioning actions	3.4			7.2
Effect on future earnings, amount				23.0
Restructuring and related cost, expected cost remaining	0.5			0.5
2017Repositioning [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges				1.7
Restructuring and related cost, expected number of positions eliminated | employee			300
Restructuring and related cost, number of positions eliminated, period percent			3.00%
Severance costs				1.0
Other restructuring costs				0.7
Other costs related to repositioning actions						$ 7.5
Effect on future earnings, amount				30.0
Restructuring and related cost, expected cost remaining	$ 5.5			5.5
2017Repositioning [Member] | cumulative [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges				31.4
Severance costs				31.3
Other restructuring costs				$ 0.1