| Current Federal Tax Expense (Benefit) | 3.43M | 2025-01-01 → 2025-12-31 |
| Current State and Local Tax Expense (Benefit) | 6.89M | 2025-01-01 → 2025-12-31 |
| Current Income Tax Expense (Benefit) | 10.32M | 2025-01-01 → 2025-12-31 |
| Cash and Cash Equivalents, Fair Value Disclosure | 1.88B | as of 2025-12-31 |
| Deferred Federal Income Tax Expense (Benefit) | 408.85M | 2025-01-01 → 2025-12-31 |
| Deferred State and Local Income Tax Expense (Benefit) | 85.76M | 2025-01-01 → 2025-12-31 |
| Operating Lease, Liability, Current | 67.68M | as of 2025-12-31 |
| Asset Retirement Obligation, Revision of Estimate | -9.00M | 2025-01-01 → 2025-12-31 |
| Other Tax Expense (Benefit) | -6.97M | 2025-01-01 → 2025-12-31 |
| Prepaid Expense and Other Assets, Current | 424.70M | as of 2025-12-31 |
| Dividends, Preferred Stock, Cash | 18.32M | 2025-01-01 → 2025-12-31 |
| Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity | 180.73M | 2025-01-01 → 2025-12-31 |
| Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount | 476.97M | 2025-01-01 → 2025-12-31 |
| Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount | 92.94M | 2025-01-01 → 2025-12-31 |
| Energy Related Inventory | 131.97M | as of 2025-12-31 |
| Long-term Debt, Fair Value | 28.21B | as of 2025-12-31 |
| Equity Securities, FV-NI, Unrealized Gain (Loss) | 475.00M | 2025-01-01 → 2025-12-31 |
| Public Utilities, Property, Plant and Equipment, Transmission | 11.12B | as of 2025-12-31 |
| Public Utilities, Property, Plant and Equipment, Distribution | 16.37B | as of 2025-12-31 |
| Public Utilities, Property, Plant and Equipment, Fuel | 834.69M | as of 2025-12-31 |
| Public Utilities, Property, Plant and Equipment, Construction Work in Progress | 6.02B | as of 2025-12-31 |
| Deferred Costs and Other Assets | 6.01B | as of 2025-12-31 |
| SegmentExpenditureAdditionToLongLivedAssets | 8.21B | 2025-01-01 → 2025-12-31 |
| Public Utilities, Property, Plant and Equipment, Other Property, Plant and Equipment | 2.20B | as of 2025-12-31 |
| Dividends, Common Stock, Cash | 1.07B | 2025-01-01 → 2025-12-31 |
| Public Utilities, Property, Plant and Equipment, Plant in Service | 81.61B | as of 2025-12-31 |
| Public Utilities, Property, Plant and Equipment, Accumulated Depreciation | 28.75B | as of 2025-12-31 |
| Public Utilities, Property, Plant and Equipment, Net | 52.85B | as of 2025-12-31 |
| Effective Income Tax Rate Reconciliation, Tax Settlement, State and Local, Amount | 0 | 2025-01-01 → 2025-12-31 |
| Effective Income Tax Rate Reconciliation, Tax Settlement, Amount | 0 | 2025-01-01 → 2025-12-31 |
| Debt Securities, Available-for-sale, Unrealized Gain | 28.00M | 2025-01-01 → 2025-12-31 |
| Debt Securities, Available-for-sale, Unrealized Loss | 45.00M | 2025-01-01 → 2025-12-31 |
| Debt Securities, Available-for-sale, Realized Gain | 6.00M | 2025-01-01 → 2025-12-31 |
| Debt Securities, Available-for-sale, Realized Loss | 13.00M | 2025-01-01 → 2025-12-31 |
| Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount | 0 | 2025-01-01 → 2025-12-31 |
| Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount | 4.13M | 2025-01-01 → 2025-12-31 |
| Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount | 3.36M | 2025-01-01 → 2025-12-31 |
| Loss Contingency Accrual | 495.78M | as of 2025-12-31 |
| Revenue, Remaining Performance Obligation, Amount | 8.04B | as of 2025-12-31 |
| Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One | 31.00M | as of 2025-12-31 |
| Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five | 649.00M | as of 2025-12-31 |
| Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 | 645.00M | as of 2025-12-31 |
| Deferred Income Taxes and Other Tax Liabilities, Noncurrent | 5.59B | as of 2025-12-31 |
| Deferred Credits and Other Liabilities | 953.08M | as of 2025-12-31 |
| StockRepurchaseProgramAuthorizedAmount1 | 500.00M | as of 2025-12-31 |
| Stock Repurchase Program, Remaining Authorized Repurchase Amount | 350.00M | as of 2025-12-31 |
| Contract with Customer, Refund Liability, Current | 479.80M | as of 2025-12-31 |
| Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | 3.00M | as of 2025-12-31 |
| Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 42.00M | as of 2025-12-31 |
| Debt Securities, Available-for-sale, Unrealized Loss Position | 45.00M | as of 2025-12-31 |
| Deferred Tax Assets, Operating Loss Carryforwards | 2.76B | as of 2025-12-31 |
| Stock Issued During Period, Value, New Issues | 1.15B | 2025-01-01 → 2025-12-31 |
| Deferred Tax Assets, Tax Credit Carryforwards | 49.25M | as of 2025-12-31 |
| Deferred Tax Assets, Capital Loss Carryforwards | 145.63M | as of 2025-12-31 |
| Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Pensions | 27.72M | as of 2025-12-31 |
| Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Compensation | 87.84M | as of 2025-12-31 |
| Liability, Defined Benefit Plan, Current | 63.21M | as of 2025-12-31 |
| Operating Lease, Cost | 76.64M | 2025-01-01 → 2025-12-31 |
| Short-term Lease, Cost | 4.20M | 2025-01-01 → 2025-12-31 |
| Public Utilities, Inventory | 1.71B | as of 2025-12-31 |
| Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Contingencies | 191.29M | as of 2025-12-31 |
| Finance Lease, Liability, to be Paid, Year One | 24.80M | as of 2025-12-31 |
| Finance Lease, Liability, to be Paid, Year Two | 22.61M | as of 2025-12-31 |
| Finance Lease, Liability, to be Paid, Year Three | 20.14M | as of 2025-12-31 |
| Finance Lease, Liability, to be Paid, Year Four | 16.08M | as of 2025-12-31 |
| Finance Lease, Liability, to be Paid, Year Five | 12.04M | as of 2025-12-31 |
| Finance Lease, Liability, to be Paid, after Year Five | 52.67M | as of 2025-12-31 |
| Finance Lease, Liability, Payment, Due | 148.35M | as of 2025-12-31 |
| Accounts Receivable, Allowance for Credit Loss, Writeoff | 78.10M | 2025-01-01 → 2025-12-31 |
| Accounts Receivable, Allowance for Credit Loss, Recovery | 33.80M | 2025-01-01 → 2025-12-31 |
| Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease) | 58.70M | 2025-01-01 → 2025-12-31 |
| Deferred Tax Assets, Unrealized Losses on Available-for-Sale Securities, Gross | 0 | as of 2025-12-31 |
| Lessee, Operating Lease, Liability, to be Paid, Year One | 78.08M | as of 2025-12-31 |
| Deferred Tax Assets, Deferred Income | -3.59M | as of 2025-12-31 |
| Lessee, Operating Lease, Liability, to be Paid, Year Two | 66.34M | as of 2025-12-31 |
| Lessee, Operating Lease, Liability, to be Paid, Year Three | 53.74M | as of 2025-12-31 |
| Deferred Tax Assets, Regulatory Assets and Liabilities | 1.33B | as of 2025-12-31 |
| Lessee, Operating Lease, Liability, to be Paid, Year Four | 38.67M | as of 2025-12-31 |
| Lessee, Operating Lease, Liability, to be Paid, Year Five | 24.30M | as of 2025-12-31 |
| Lessee, Operating Lease, Liability, to be Paid, after Year Five | 51.93M | as of 2025-12-31 |
| Utilities Operating Expense, Purchased Power | 1.24B | 2025-01-01 → 2025-12-31 |
| Lessee, Operating Lease, Liability, to be Paid | 313.06M | as of 2025-12-31 |
| Utilities Operating Expense, Fuel Used | 2.36B | 2025-01-01 → 2025-12-31 |
| Deferred Tax Assets, Other | 167.21M | as of 2025-12-31 |
| Deferred Tax Assets, Valuation Allowance | 335.11M | as of 2025-12-31 |
| Deferred Tax Assets, Net of Valuation Allowance | 4.59B | as of 2025-12-31 |
| Deferred Tax Liabilities, Property, Plant and Equipment | 7.18B | as of 2025-12-31 |
| Deferred Tax Liabilities, Regulatory Assets | 1.03B | as of 2025-12-31 |
| Assets, Fair Value Disclosure | 8.52B | as of 2025-12-31 |
| Other Comprehensive Income (Loss), before Reclassifications, Net of Tax | -28.98M | 2025-01-01 → 2025-12-31 |
| Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax | 16.80M | 2025-01-01 → 2025-12-31 |
| Financial and Nonfinancial Liabilities, Fair Value Disclosure | 8.00M | as of 2025-12-31 |
| Deferred Tax Liabilities, Other | 161.27M | as of 2025-12-31 |
| Deferred Tax Liabilities, Net | 9.31B | as of 2025-12-31 |
| Long-Term Debt, Maturity, Year One | 2.38B | as of 2025-12-31 |
| Defined Contribution Plan, Cost | 77.40M | 2025-01-01 → 2025-12-31 |
| Long-Term Debt, Maturity, Year Two | 1.05B | as of 2025-12-31 |
| Long-Term Debt, Maturity, Year Three | 2.16B | as of 2025-12-31 |
| Long-Term Debt, Maturity, Year Four | 405.72M | as of 2025-12-31 |
| Long-Term Debt, Maturity, Year Five | 916.82M | as of 2025-12-31 |
| Debt Instrument, Unamortized Discount (Premium), Net | -23.44M | as of 2025-12-31 |
| Unrecognized Tax Benefits | 3.19B | as of 2025-12-31 |
| Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions | 590.47M | 2025-01-01 → 2025-12-31 |
| Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions | 23.17M | 2025-01-01 → 2025-12-31 |
| Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions | 272.76M | 2025-01-01 → 2025-12-31 |
| Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities | 0 | 2025-01-01 → 2025-12-31 |
| Unrecognized Tax Benefits, Interest on Income Taxes Expense | 10.00M | 2025-01-01 → 2025-12-31 |
| Unrecognized Tax Benefits, Interest on Income Taxes Accrued | 42.00M | as of 2025-12-31 |
| Unrecognized Tax Benefits that Would Impact Effective Tax Rate | 2.78B | as of 2025-12-31 |
| Other Receivables | 242.40M | as of 2025-12-31 |
| Allowance for Doubtful Other Receivables, Current | 32.30M | as of 2025-12-31 |
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value | 27.00M | as of 2025-12-31 |
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Issuances | 49.00M | 2025-01-01 → 2025-12-31 |
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements | 195.00M | 2025-01-01 → 2025-12-31 |
| Debt Securities, Available-for-sale, Amortized Cost | 2.22B | as of 2025-12-31 |
| Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value | 361.00M | as of 2025-12-31 |
| Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value | 549.00M | as of 2025-12-31 |
| Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value | 910.00M | as of 2025-12-31 |