Other (expense), net (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Intercompany Foreign Currency Balance [Line Items]
Postretirement expense	$ (167.7)	$ (22.7)
Foreign exchange losses	(2.9)	(15.6)
Environmental costs and other, net	(12.0)	(9.8)
Total other expense, net	(182.6)	(48.1)
Liquidation of Foreign Subsidiaries
Intercompany Foreign Currency Balance [Line Items]
Foreign exchange losses	(2.3)	$ (19.0)
Pension Plans
Intercompany Foreign Currency Balance [Line Items]
Settlement loss	158.0
Pension Plans | United States
Intercompany Foreign Currency Balance [Line Items]
Settlement loss	$ 158.0