Impairment and Restructuring Charges (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Impairment and Restructuring Charges
Property, plant and equipment	$ 3.8	$ 4.2	$ 16.0
Intangible assets, net	33.2		36.4
Total impairment charges	37.0	4.2	52.4
Total impairment and restructuring charges	39.5	4.1	69.1
Cost of sales
Impairment and Restructuring Charges
Restructuring		(0.2)	12.8
Warehouse, delivery, selling, general and administrative expense
Impairment and Restructuring Charges
Restructuring	$ 2.5	$ 0.1	2.9
Non-operating expense
Impairment and Restructuring Charges
Restructuring			$ 1.0