Other Expense Restructuring and Related Charges (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Severance charges	$ 0.0	$ 8.9	$ 0.0
Asset impairment charges, trademark		10.0
Asset impairment charges, patent and equipment		7.3
Other restructuring charges	0.0	0.2	0.0
Restructuring Reserve [Roll Forward]
Restructuring Reserve	2.1	5.9	0.0
Charges	0.0	26.4	0.0
Cash payments	(3.1)	(3.0)
Non-cash asset write-downs	(0.7)	(17.5)	0.0
Severance and benefits [Member]
Restructuring Reserve [Roll Forward]
Restructuring Reserve	2.1	5.9	0.0
Charges	(0.7)	8.9
Cash payments	(3.1)	(3.0)
Non-cash asset write-downs	0.0	0.0
Asset-related charges [Member]
Restructuring Reserve [Roll Forward]
Restructuring Reserve	0.0	0.0	0.0
Charges	0.0	17.3
Cash payments	0.0	0.0
Non-cash asset write-downs	0.0	(17.3)
Other charges [Member]
Restructuring Reserve [Roll Forward]
Restructuring Reserve	0.0	0.0	$ 0.0
Charges	0.7	0.2
Cash payments	0.0	0.0
Non-cash asset write-downs	$ (0.7)	$ (0.2)