Basis of presentation (Details) $ in Millions		3 Months Ended
		Mar. 31, 2022 USD ($) segment $ / $	Mar. 31, 2021 USD ($) $ / $	Dec. 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		$ 15.4
Net monetary assets		2,083.9		$ 1,999.5
Cash and cash equivalents		733.0		710.3
Goodwill		1,423.2		1,411.7
Restricted cash		313.2		376.4
Cumulative effect of change in accounting principle		369.8	$ 225.1	$ 252.6		$ 202.5
Uncollectible Receivables
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in allowance estimate		$ 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		7.00%	8.00%	19.00%
Official exchange rate | $ / $		111.1	91.7	103.1		84.0
Currency remeasurement loss		$ 4.9	$ 3.0
Net monetary assets		69.0		$ 60.1
Cash and cash equivalents		62.7		52.9
Nonmonetary assets		154.0		155.3
Goodwill		99.8		99.8
Equity securities		7.8		8.2
Debt securities		4.1		4.3
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principle		374.7	$ 413.3	312.9		$ 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		$ 15.0		$ 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.