Restructuring and Repositioning Expenses, Asset Impairments - Restructuring Costs by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses and asset impairments from continuing operations	$ 3.1	$ 0.6
Restructuring expenses and asset impairments reflected in discontinued operations	0.0	0.1
Total restructuring expenses and asset impairments	3.1	0.7
Operating Segments | SCC
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses and asset impairments from continuing operations	2.3	0.6
Operating Segments | SBM
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses and asset impairments from continuing operations	0.8	0.0
Corporate
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses and asset impairments from continuing operations	$ 0.0	$ 0.0