Basis of presentation (Details)	3 Months Ended						12 Months Ended
	Mar. 31, 2020 USD ($) segment $ / $		Dec. 31, 2019 USD ($) $ / $	Sep. 30, 2019 USD ($)	Mar. 31, 2019 USD ($) $ / $		Dec. 31, 2019 USD ($) $ / $	Jan. 01, 2020 USD ($)	Jan. 01, 2019 USD ($)	Dec. 31, 2018 $ / $
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of operating segments | segment	3
Net monetary assets	$ 1,339,000,000.0		$ 1,232,600,000				$ 1,232,600,000
Cash and cash equivalents	274,400,000		311,000,000.0				311,000,000.0
Goodwill	794,400,000		784,600,000				784,600,000
Revenues	872,800,000				$ 905,000,000.0
Provision for doubtful accounts	37,300,000		30,200,000				30,200,000
Cumulative effect of change in accounting principle	(1,700,000)	[1]			$ 0	[2]
Right-of-use assets, net	$ 261,100,000		$ 270,300,000				$ 270,300,000
Argentina, Pesos | Argentina
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Percent of Consolidated Revenue	5.00%				6.00%
Rate decrease percent	7.00%		37.00%		13.00%		37.00%
Official exchange rate | $ / $	64.5		59.9		43.3		59.9			37.6
Net remeasurement loss	$ (1,600,000)				$ 3,900,000
Net monetary assets	22,800,000
Cash and cash equivalents	19,700,000
Nonmonetary assets	151,000,000.0
Goodwill	99,800,000
Equity Securities	0
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principle	(1,700,000)	[1]			$ 28,800,000	[2]
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets, net									$ 310,100,000
Lease liabilities									320,300,000
Accounting Standards Update 2018-02 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principle									$ 28,800,000
Accounting Standards Update 2016-13 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principle								$ 1,700,000
Internal Loss AR Rebuild
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Third-party expense	200,000						$ 4,500,000
Revenues				$ 4,000,000.0
Bank fees				300,000
Increase to bad debt expense	9,400,000		$ 6,400,000	$ 13,700,000
Provision for doubtful accounts	23,000,000.0
Accounts receivable	$ 30,200,000
Percent of Accounts Receivable	76.00%

[1] Effective January 1, 2020, we adopted the provisions of ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. We recognized a cumulative effect adjustment to January 1, 2020 retained earnings as a result of adopting this standard. See Note 1 for further details.

[2] Effective January 1, 2019, we adopted the provisions of ASU 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. We recognized a cumulative effect adjustment to January 1, 2019 retained earnings as a result of adopting this standard. See Note 1 for further details.