Restructuring Activities - Restructuring Charges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Restructuring Cost and Reserve
Severance costs	$ 0.2	$ 1.2	$ 0.8	$ 2.5
Other restructuring costs	0.4	3.8	0.7	7.1
Restructuring costs	0.6	5.0	1.5	9.6
Cost of sales
Restructuring Cost and Reserve
Severance costs	0.0	0.1	0.1	0.7
Other restructuring costs	0.4	2.0	0.6	3.8
Selling, general, and administrative expenses
Restructuring Cost and Reserve
Severance costs	0.2	1.1	0.7	1.8
Other restructuring costs	$ 0.0	$ 1.8	$ 0.1	$ 3.3