Credit losses (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($) country
Valuation Allowance [Line Items]
Number of Countries in which Entity Operates | country	100
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for doubtful accounts, beginning balance	$ 30.7
Provision for uncollectible accounts receivable(a)	7.0
Write-offs and recoveries	(2.1)
Foreign currency exchange effects	(0.6)
Allowance for doubtful accounts, ending balance	35.0
Internal Loss AR Rebuild
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Provision for uncollectible accounts receivable(a)	1.6
Allowance for doubtful accounts, ending balance	$ 11.0