Basis of presentation (Details) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2022 USD ($) $ / $	Mar. 31, 2022 USD ($)	Jun. 30, 2022 USD ($) segment $ / $	Jun. 30, 2021 USD ($) $ / $	Dec. 31, 2021 USD ($) $ / $	Mar. 31, 2021 USD ($)	Jan. 01, 2021 USD ($)	Dec. 31, 2020 USD ($) $ / $
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of operating segments | segment				4
Change in allowance estimate				$ 19.9
Net monetary assets		$ 2,222.3		2,222.3		$ 1,999.5
Cash and cash equivalents		743.3		743.3		710.3
Goodwill		1,379.8		1,379.8		1,411.7
Restricted cash		358.6		358.6		376.4
Cumulative effect of change in accounting principle		366.7	$ 369.8	$ 366.7	$ 302.6	$ 252.6	$ 225.1		$ 202.5
Uncollectible Receivables
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in allowance estimate		$ 0.4	16.7
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principle	[1]								$ 0.5
Argentina, Pesos | Argentina
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Percent of Consolidated Revenue				5.00%	4.00%
Rate decrease percent		18.00%		18.00%	13.00%	19.00%
Official exchange rate | $ / $		125.0		125.0	96.2	103.1			84.0
Currency remeasurement loss				$ 13.4	$ 5.0
Net monetary assets		$ 75.8		75.8		$ 60.1
Cash and cash equivalents		68.0		68.0		52.9
Nonmonetary assets		152.6		152.6		155.3
Goodwill		99.8		99.8		99.8
Equity securities		7.7		7.7		8.2
Debt securities		3.7		3.7		4.3
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principle		408.8	$ 374.7	408.8	$ 427.2	312.9	$ 413.3		$ 407.5
Retained Earnings | Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principle	[1]								$ 0.5
Accounting Standards Update 2019-12 | Retained Earnings | Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principle								$ 0.5
Revolving Credit Facility
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash		$ 22.5		$ 22.5		$ 15.0

[1] Effective January 1, 2021, we adopted the provisions of ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. We recognized a cumulative effect adjustment to January 1, 2021 retained earnings as a result of adopting this standard. See Note 1 for further details.