v3.25.2
Stockholders' Equity, Accumulated Other Comprehensive Income (Loss) and Noncontrolling Interest - Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Amortization of Defined Benefit Pension and Other Post-retirement Benefit Plan Items, Actuarial Gain [Member]        
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]        
Reclassifications out of AOCI $ (0.6) $ (0.7) $ (1.2) $ (1.5)
Amortization of Defined Benefit Pension and Other Post-retirement Benefit Plan Items, Pension Settlement Loss (Gain) [Member]        
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]        
Reclassifications out of AOCI (0.3) (0.6) (0.5) 1.1
Accumulated Defined Benefit Plans Adjustment Net Curtailment Including Portion Attributable To Noncontrolling Interest [Member]        
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]        
Reclassifications out of AOCI       (0.3)
Amortization of Defined Benefit Pension and Other Post-retirement Benefit Plan Items [Member]        
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]        
Reclassifications out of AOCI (0.9) (1.3) (1.7) (0.7)
Tax expense 0.6 0.3 0.4  
Net of tax $ (0.3) $ (1.0) $ (1.3) $ (0.7)