v3.25.4
Income Taxes (Schedule Of Components Of Income Tax Expense) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Current      
Federal $ (30.4) $ (19.3) $ 0.0
State (1.6) 9.4 5.3
Total Current (32.0) (9.9) 5.3
Deferred      
Federal 411.4    
Investment Tax Credit (32.4) (14.5) (2.1)
State 13.1 2.6 22.5
Total Deferred 236.5 168.8 135.2
Deferred Investment Credits (0.7) (0.8) (1.0)
Income Taxes $ 203.8 $ 158.1 $ 139.5
Effective Income Tax Rate Reconciliation, Tax Credit, Investment, Percent (2.70%) (1.50%) (0.30%)
Production tax credit $ (40.5) $ (5.8) $ (0.3)
Production tax credit, Percent (3.30%) (0.60%) 0.00%
Other tax credits $ (3.1) $ (3.0) $ (1.5)
Other tax credits, percent (0.30%) (0.30%) (0.20%)
Excess Deferred Income Taxes - ITC / PTC, Percent 5.60% 2.00% 0.00%
Excess Deferred Income Taxes - ITC / PTC $ 68.2 $ 20.0 $ 0.0
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount 8.4    
Effective Income Tax Rate Reconciliation, Noncontrolling Interest Income (Loss), Amount $ (18.2) $ (27.3) $ 0.0
Effective Income Tax Rate Reconciliation, Noncontrolling Interest Income (Loss), Percent (1.50%) (2.70%) 0.00%
Deferred income taxes and investment tax credits $ (30.2) $ (31.2) $ (39.2)
Effective Income Tax Rate Reconciliation, Tax Contingency, Other, Percent (2.50%) (3.10%) (4.80%)
Valuation Allowance, Deferred Tax Asset, Explanation of Change  
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent 0.70% 0.00% 0.00%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amount $ (5.5) $ (12.5) $ (5.3)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent (0.40%) (1.20%) (0.70%)
State regulatory proceedings, rate (0.10%) 0.80% 0.90%
State regulatory proceedings, value $ 1.2 $ 7.6 $ 7.8
Book income before income taxes 1,216.4 1,002.8 813.9
Tax expense (benefit) at statutory federal income tax rate, value $ 255.4 $ 210.6 $ 170.8
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent 21.00% 21.00% 21.00%
State income taxes, net of federal income tax benefit, value $ 4.9 $ 11.7 $ 13.7
State income taxes, net of federal income tax benefit, rate 0.40% 1.20% 1.70%
Other adjustments, value $ (4.4) $ 2.5 $ (4.4)
Other adjustments, rate 0.30% 0.20% (0.50%)
Effective Income Tax Rate Reconciliation, Percent 16.80% 15.80% 17.10%
Investment Tax Credit Carryforward      
Deferred      
Federal $ 31.0    
Investment Tax Credit 0.0 $ (0.1) $ (2.1)
Operating loss carryforward and investment credits      
Deferred      
Federal 189.2 105.9 49.7
Utilization expense of operating loss carryforwards      
Deferred      
Federal $ 34.2 $ 60.4 $ 65.1