v3.26.1
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, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
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) $ (0.1) $ (1.2)
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) (0.3) (0.5) (0.5)
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 (0.3) (0.9) (0.6) (1.7)
Tax expense 0.1 0.6 0.2 0.4
Net of tax $ (0.2) $ (0.3) $ (0.4) $ (1.3)