v3.26.1
Reclassifications Out of Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss (Detail) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Beginning Balance $ 1,326.1  
Ending Balance 1,343.4  
Accumulated Other Comprehensive Loss [Member]    
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Beginning Balance (34.7) $ (91.0)
Other comprehensive income/(loss) before reclassifications (11.2) 57.6
Amounts reclassified from AOCL 0.0 0.0
Total other comprehensive income/(loss) (11.2) 57.6
Ending Balance (45.9) (33.4)
Defined Benefit Pension Plan Items [Member]    
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Beginning Balance 0.9 0.0
Other comprehensive income/(loss) before reclassifications 0.0 0.0
Amounts reclassified from AOCL 0.0 0.0
Total other comprehensive income/(loss) 0.0 0.0
Ending Balance 0.9 0.0
Foreign Currency Translation Items [Member]    
Accumulated Other Comprehensive Income (Loss) [Line Items]    
Beginning Balance (35.6) (91.0)
Other comprehensive income/(loss) before reclassifications (11.2) 57.6
Amounts reclassified from AOCL 0.0 0.0
Total other comprehensive income/(loss) (11.2) 57.6
Ending Balance $ (46.8) $ (33.4)