Restructuring Activities - Restructuring Activities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Continuing Operations:
Restructuring charges	$ 8.6	$ 1.9
Total charges	10.8	4.1
Capital expenditures	0.2	9.9
Continuing Operations
Continuing Operations:
Other associated costs	2.2	3.9
Restructuring charges	8.6	1.9
Total charges	10.8	5.8
Discontinued Operations
Continuing Operations:
Total charges	$ 0.0	$ (1.7)