Restructuring Activities - Restructuring Charges (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve
Total severance costs	$ 3.2	$ 3.6	$ 8.6
Total other restructuring costs	1.2	7.6	0.9
Restructuring costs	4.4	11.2	9.5
Cost of sales
Restructuring Cost and Reserve
Total severance costs	0.0	0.4	3.3
Total other restructuring costs	0.8	2.3	0.2
Selling, general, and administrative expenses
Restructuring Cost and Reserve
Total severance costs	3.2	3.2	5.3
Total other restructuring costs	$ 0.4	$ 5.3	$ 0.7