Property, plant and equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 752.7	$ 681.7
Less: Accumulated depreciation and amortization	(210.4)	(171.5)
Total property, plant and equipment, net	542.3	510.2
Depreciation and amortization	49.5	36.3	$ 32.2
Land and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	46.5	44.6
Buildings, building improvements and leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	234.8	216.2
Furniture and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	334.2	293.9
Software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	55.7	55.2
Construction-in-progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 81.5	$ 71.8