Management Actions (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Approximate time anticipated savings will offset the restructuring charge	1 year
Restructuring Reserve [Roll Forward]
Restructuring Charges, net of noncash expenses			$ 3.4
Restructuring Reserve beginning balance	$ 2.2
Cash Payments	(0.1)	$ (2.1)
Foreign currency adjustments		(0.1)
Restructuring Reserve ending balance	6.4	2.2
Selling and Administrative Expense
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	4.3	1.0
Restructuring Reserve [Roll Forward]
Restructuring Charges	$ 4.3	$ 1.0