Leasing - Lease cost in income statement (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Lessee, Lease, Description [Line Items]
Operating Leases	$ 14.0	$ 12.6	$ 41.7	$ 37.9
Finance Leases	7.5	5.5	21.3	16.2
Total	21.5	18.1	63.0	54.1
Depreciation	6.7	4.8	18.8	14.2
Interest expense	0.8	0.7	2.5	2.0
Variable lease costs	0.2	(0.2)	0.6	0.7
Short-term lease costs	5.9	11.3	19.8	22.9
Total gross lease costs	27.6	29.2	83.4	77.7
Sublease income	0.6	1.3	1.8	2.9
Total net lease cost	27.0	27.9	81.6	74.8
Cost of goods sold (exclusive of depreciation)
Lessee, Lease, Description [Line Items]
Operating Leases	4.7	3.6	13.4	11.3
Finance Leases	0.0	0.0	0.0	0.0
Total	4.7	3.6	13.4	11.3
Outbound freight and handling
Lessee, Lease, Description [Line Items]
Operating Leases	1.5	1.9	4.2	5.6
Finance Leases	0.0	0.0	0.0	0.0
Total	1.5	1.9	4.2	5.6
Warehousing, selling and administrative
Lessee, Lease, Description [Line Items]
Operating Leases	7.8	7.1	24.1	21.0
Finance Leases	0.0	0.0	0.0	0.0
Total	$ 7.8	$ 7.1	$ 24.1	$ 21.0