Revenue recognition - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contract with customer, liability, revenue recognized	$ 139.5	$ 83.4	$ 62.4
Remaining performance obligation, amount	$ 329.1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, percentage	73.00%
Revenue, remaining performance obligation, period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, percentage	27.00%
Revenue, remaining performance obligation, period