Revenue recognition - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contract with customer, liability, revenue recognized	$ 115.2	$ 90.8	$ 157.8	$ 104.2
Remaining performance obligation, amount	$ 414.3		$ 414.3
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, percentage	70.00%		70.00%
Revenue, remaining performance obligation, period	12 months		12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, percentage	30.00%		30.00%
Revenue, remaining performance obligation, period