v3.25.2
Stockholders' equity - Schedule of Changes in Accumulated Other Comprehensive Loss (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Accumulated Other Comprehensive Income Loss [Line Items]        
Balance at beginning of period $ 847.0 $ 774.4 $ 817.0 $ 808.3
Balance at end of period 846.8 774.6 846.8 774.6
Currency translation        
Accumulated Other Comprehensive Income Loss [Line Items]        
Balance at beginning of period (282.7) (286.1) (300.0) (265.5)
Other comprehensive income (loss) 14.2 1.9 31.5 (18.7)
Balance at end of period (268.5) (284.2) (268.5) (284.2)
Accumulated Defined benefit pension plans | Defined benefit pension plans        
Accumulated Other Comprehensive Income Loss [Line Items]        
Balance at beginning of period (63.4) (75.5) (63.8) (76.0)
Other comprehensive income (loss) 0.4 0.5 0.8 1.0
Balance at end of period (63.0) (75.0) (63.0) (75.0)
Accumulated Defined benefit pension plans | OPEB Plans        
Accumulated Other Comprehensive Income Loss [Line Items]        
Balance at beginning of period 0.3 0.4 0.3 0.4
Balance at end of period 0.3 0.4 0.3 0.4
Total Accumulated Other Comprehensive Loss        
Accumulated Other Comprehensive Income Loss [Line Items]        
Balance at beginning of period (345.8) (361.2) (363.5) (341.1)
Other comprehensive income (loss) 14.6 2.4 32.3 (17.7)
Balance at end of period $ (331.2) $ (358.8) $ (331.2) $ (358.8)