Credit losses (Details) $ in Millions	6 Months Ended
	Jun. 30, 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)	3.5
Write-offs and recoveries	(3.9)
Foreign currency exchange effects	(0.4)
Allowance for doubtful accounts, ending balance	29.9
Internal Loss AR Rebuild
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Provision for uncollectible accounts receivable(a)	2.7
Allowance for doubtful accounts, ending balance	$ 9.5