Restructuring Activities - Restructuring Activities (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Continuing Operations:
Other associated costs	$ (0.4)	$ 5.9	$ 1.8	$ 9.8
Restructuring charges	7.1	1.1	15.7	3.0
Total charges	7.5	12.2	18.3	16.3
Capital expenditures	0.3	4.0	0.5	13.9
Continuing Operations
Continuing Operations:
Other associated costs	0.4	5.9	2.6	9.8
Restructuring charges	7.1	1.1	15.7	3.0
Total charges	7.5	7.0	18.3	12.8
Discontinued Operations
Continuing Operations:
Total charges	$ 0.0	$ 5.2	$ 0.0	$ 3.5