Subsequent events (Details) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Feb. 28, 2019 USD ($)	Apr. 01, 2019 segment	Dec. 31, 2018 segment
Subsequent Event [Line Items]
Number of reportable segments | segment			7
Subsequent Event
Subsequent Event [Line Items]
Number of reportable segments | segment		4
Subsequent Event | 2019 Footprint Realignment Plan | Minimum
Subsequent Event [Line Items]
Expected restructuring charges	$ 56.0
Effect on future cash flows, amount	53.0
Restrcturing costs, expected capital expenditures	29.0
Subsequent Event | 2019 Footprint Realignment Plan | Maximum
Subsequent Event [Line Items]
Expected restructuring charges	70.0
Effect on future cash flows, amount	66.0
Restrcturing costs, expected capital expenditures	35.0
Subsequent Event | 2019 Footprint Realignment Plan | Termination benefits | Minimum
Subsequent Event [Line Items]
Expected restructuring charges	19.0
Subsequent Event | 2019 Footprint Realignment Plan | Termination benefits | Maximum
Subsequent Event [Line Items]
Expected restructuring charges	23.0
Subsequent Event | 2019 Footprint Realignment Plan | Other Costs | Minimum
Subsequent Event [Line Items]
Expected restructuring charges	1.0
Subsequent Event | 2019 Footprint Realignment Plan | Other Costs | Maximum
Subsequent Event [Line Items]
Expected restructuring charges	2.0
Subsequent Event | 2019 Footprint Realignment Plan | Restructuring charges | Minimum
Subsequent Event [Line Items]
Expected restructuring charges	20.0
Subsequent Event | 2019 Footprint Realignment Plan | Restructuring charges | Maximum
Subsequent Event [Line Items]
Expected restructuring charges	25.0
Subsequent Event | 2019 Footprint Realignment Plan | Accelerated Depreciation And Other Costs | Minimum
Subsequent Event [Line Items]
Expected restructuring charges	36.0
Subsequent Event | 2019 Footprint Realignment Plan | Accelerated Depreciation And Other Costs | Maximum
Subsequent Event [Line Items]
Expected restructuring charges	45.0
Subsequent Event | 2019 Footprint Realignment Plan | Accelerated Depreciation And Other Costs | Cost of Goods Sold | Minimum
Subsequent Event [Line Items]
Expected restructuring charges	3.0
Subsequent Event | 2019 Footprint Realignment Plan | Accelerated Depreciation And Other Costs | Cost of Goods Sold | Maximum
Subsequent Event [Line Items]
Expected restructuring charges	$ 4.0