v3.25.2
Share-based compensation plans - Compensation Expense (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based payment expense $ 8.6 $ 8.0 $ 14.6 $ 18.0
Cash based awards 0.5 0.7 0.8 1.4
Income tax benefit (1.9) (1.8) (3.3) (4.1)
Share-based payment expense, net of tax 6.7 6.2 11.3 13.9
Performance Shares Units        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based payment expense 4.7 4.4 7.7 10.8
Restricted Stock Units        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based payment expense 3.1 2.6 5.4 5.1
Deferred Stock Units        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based payment expense $ 0.3 $ 0.3 $ 0.7 $ 0.7