Revenue from contracts with customers - Disaggregation of revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Revenue disaggregated by reportable segment and type of service	$ 4,874.6	$ 4,535.5	$ 4,200.2
Reportable Segments
Disaggregation of Revenue [Line Items]
Revenue disaggregated by reportable segment and type of service	4,874.6	4,535.5	4,200.2
Reportable Segments | Cash and valuables management
Disaggregation of Revenue [Line Items]
Revenue disaggregated by reportable segment and type of service	3,862.7	3,792.1	3,669.8
Reportable Segments | DRS and AMS
Disaggregation of Revenue [Line Items]
Revenue disaggregated by reportable segment and type of service	1,011.9	743.4	530.4
North America | Reportable Segments
Disaggregation of Revenue [Line Items]
Revenue disaggregated by reportable segment and type of service	1,601.1	1,584.1	1,407.1
North America | Reportable Segments | Cash and valuables management
Disaggregation of Revenue [Line Items]
Revenue disaggregated by reportable segment and type of service	1,216.8	1,207.2	1,122.3
North America | Reportable Segments | DRS and AMS
Disaggregation of Revenue [Line Items]
Revenue disaggregated by reportable segment and type of service	384.3	376.9	284.8
Latin America | Reportable Segments
Disaggregation of Revenue [Line Items]
Revenue disaggregated by reportable segment and type of service	1,332.3	1,210.6	1,126.0
Latin America | Reportable Segments | Cash and valuables management
Disaggregation of Revenue [Line Items]
Revenue disaggregated by reportable segment and type of service	1,149.1	1,090.3	1,030.9
Latin America | Reportable Segments | DRS and AMS
Disaggregation of Revenue [Line Items]
Revenue disaggregated by reportable segment and type of service	183.2	120.3	95.1
Europe | Reportable Segments
Disaggregation of Revenue [Line Items]
Revenue disaggregated by reportable segment and type of service	1,136.8	931.4	917.3
Europe | Reportable Segments | Cash and valuables management
Disaggregation of Revenue [Line Items]
Revenue disaggregated by reportable segment and type of service	745.2	728.1	802.6
Europe | Reportable Segments | DRS and AMS
Disaggregation of Revenue [Line Items]
Revenue disaggregated by reportable segment and type of service	391.6	203.3	114.7
Rest of World | Reportable Segments
Disaggregation of Revenue [Line Items]
Revenue disaggregated by reportable segment and type of service	804.4	809.4	749.8
Rest of World | Reportable Segments | Cash and valuables management
Disaggregation of Revenue [Line Items]
Revenue disaggregated by reportable segment and type of service	751.6	766.5	714.0
Rest of World | Reportable Segments | DRS and AMS
Disaggregation of Revenue [Line Items]
Revenue disaggregated by reportable segment and type of service	$ 52.8	$ 42.9	$ 35.8