v3.25.4
Income Tax Provision - Effect of Temporary Differences Giving Rise to Deferred Tax Assets and Liabilities (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Deferred tax liabilities:    
Depreciation $ (60.3) $ (69.5)
Long-term contract adjustments (6.0) 0.0
Prepaid insurance (1.5) (1.3)
Leases - right-of-use asset (2.8) (2.8)
Deferred tax liabilities (70.6) (73.6)
Deferred tax assets:    
Tax loss carryforwards 23.4 15.6
Pension and postretirement benefits 29.4 41.2
Other employee benefit accruals 9.2 8.4
Lease liability 2.8 2.8
State decoupling 0.9 1.2
Capital loss carryforward 0.8 0.8
Capitalized R&D 1.7 3.0
Other, net 1.5 1.3
Deferred tax assets subtotal 69.7 74.3
Valuation allowances (16.0) (15.0)
Deferred tax assets 53.7 59.3
Net deferred tax assets (liabilities) $ (16.9) $ (14.3)