Cost Reduction Plan - Summary of the CIP Reserve Activity (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Nov. 30, 2015
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	$ 13.8	$ 8.9	$ 12.6	$ 0.0
Accrual	0.0	28.3	2.3	15.6
Payments	(1.2)	(3.8)	(2.8)	(1.8)
Adjustments			(3.2)
Restructuring reserve, ending balance	12.6	33.4	8.9	13.8
Severance
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	11.1	6.8	10.9	0.0
Accrual	(0.2)	26.1	0.0	12.9
Payments	0.0	(2.9)	(0.9)	(1.8)
Adjustments			(3.2)
Restructuring reserve, ending balance	10.9	30.0	6.8	11.1
Retention
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	2.7	2.1	1.7	0.0
Accrual	0.2	2.2	2.3	2.7
Payments	(1.2)	(0.9)	(1.9)	0.0
Adjustments			0.0
Restructuring reserve, ending balance	$ 1.7	$ 3.4	$ 2.1	$ 2.7