| Finance Lease, Right-of-Use Asset, before Accumulated Amortization | 48.00M | as of 2025-12-31 |
| Current Federal Tax Expense (Benefit) | 58.00M | 2025-01-01 → 2025-12-31 |
| Current State and Local Tax Expense (Benefit) | 11.00M | 2025-01-01 → 2025-12-31 |
| Current Income Tax Expense (Benefit) | 69.00M | 2025-01-01 → 2025-12-31 |
| Cash and Cash Equivalents, Fair Value Disclosure | 17.00M | as of 2025-12-31 |
| Deferred Federal Income Tax Expense (Benefit) | 135.00M | 2025-01-01 → 2025-12-31 |
| Deferred State and Local Income Tax Expense (Benefit) | 88.00M | 2025-01-01 → 2025-12-31 |
| Asset Retirement Obligation, Liabilities Incurred | 1.00M | 2025-01-01 → 2025-12-31 |
| Asset Retirement Obligation, Liabilities Settled | 154.00M | 2025-01-01 → 2025-12-31 |
| Operating Lease, Liability, Current | 60.00M | as of 2025-12-31 |
| Asset Retirement Obligation, Revision of Estimate | -51.00M | 2025-01-01 → 2025-12-31 |
| Share-based Payment Arrangement, Amount Capitalized | 39.00M | 2025-01-01 → 2025-12-31 |
| Accrued Employee Benefits, Current | 286.00M | as of 2025-12-31 |
| Share-based Payment Arrangement, Expensed and Capitalized, Amount | 85.00M | 2025-01-01 → 2025-12-31 |
| Other Assets, Fair Value Disclosure | 56.00M | as of 2025-12-31 |
| Real Estate Taxes and Insurance | 735.00M | 2025-01-01 → 2025-12-31 |
| Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity | 108.00M | 2025-01-01 → 2025-12-31 |
| Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount | 327.00M | 2025-01-01 → 2025-12-31 |
| Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount | 109.00M | 2025-01-01 → 2025-12-31 |
| Share-based Payment Arrangement, Expense, Tax Benefit | 1.00M | 2025-01-01 → 2025-12-31 |
| Share-based Payment Arrangement, Exercise of Option, Tax Benefit | 7.00M | 2025-01-01 → 2025-12-31 |
| Effective Income Tax Rate Reconciliation, Tax Credit, Amount | 5.00M | 2025-01-01 → 2025-12-31 |
| Public Utilities, Property, Plant and Equipment, Construction Work in Progress | 3.39B | as of 2025-12-31 |
| SegmentExpenditureAdditionToLongLivedAssets | 4.71B | 2025-01-01 → 2025-12-31 |
| Effective Income Tax Rate Reconciliation, Tax Contingency, Amount | 1.00M | 2025-01-01 → 2025-12-31 |
| SegmentReportingOtherItemAmount | 6.89B | 2025-01-01 → 2025-12-31 |
| Public Utilities, Property, Plant and Equipment, Plant in Service | 56.21B | as of 2025-12-31 |
| Public Utilities, Property, Plant and Equipment, Net | 44.41B | as of 2025-12-31 |
| Effective Income Tax Rate Reconciliation, Equity in Earnings (Losses) of Unconsolidated Subsidiary, Amount | -13.00M | 2025-01-01 → 2025-12-31 |
| Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount | 3.00M | 2025-01-01 → 2025-12-31 |
| Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount | 2.00M | 2025-01-01 → 2025-12-31 |
| Guarantor Obligations, Maximum Exposure, Undiscounted | 1.05B | as of 2025-12-31 |
| Guarantor Obligations, Current Carrying Value | 1.10B | as of 2025-12-31 |
| Net Regulatory Assets | -356.00M | as of 2025-12-31 |
| Defined Benefit Plan, Plan Assets, Period Increase (Decrease) | 253.00M | 2025-01-01 → 2025-12-31 |
| Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided | 1.43B | as of 2025-12-31 |
| Unrecorded Unconditional Purchase Obligation | 14.00M | as of 2025-12-31 |
| Operating Lease, Cost | 113.00M | 2025-01-01 → 2025-12-31 |
| Short-term Lease, Cost | 45.00M | 2025-01-01 → 2025-12-31 |
| Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits | 249.00M | as of 2025-12-31 |
| Lease, Cost | 118.00M | 2025-01-01 → 2025-12-31 |
| Right-of-Use Asset Obtained in Exchange for Finance Lease Liability | 0 | 2025-01-01 → 2025-12-31 |
| Right-of-Use Asset Obtained in Exchange for Operating Lease Liability | 104.00M | 2025-01-01 → 2025-12-31 |
| Finance Lease, Liability, to be Paid, Year One | 4.00M | as of 2025-12-31 |
| Finance Lease, Liability, to be Paid, Year Two | 3.00M | as of 2025-12-31 |
| Finance Lease, Liability, to be Paid, Year Three | 4.00M | as of 2025-12-31 |
| Finance Lease, Liability, to be Paid, Year Four | 0 | as of 2025-12-31 |
| Finance Lease, Liability, to be Paid, Year Five | 0 | as of 2025-12-31 |
| Finance Lease, Liability, to be Paid, after Year Five | 0 | as of 2025-12-31 |
| Finance Lease, Liability, Payment, Due | 11.00M | as of 2025-12-31 |
| Finance Lease, Liability, Undiscounted Excess Amount | 1.00M | as of 2025-12-31 |
| Lessee, Operating Lease, Liability, to be Paid, Year One | 72.00M | as of 2025-12-31 |
| Lessee, Operating Lease, Liability, to be Paid, Year Two | 61.00M | as of 2025-12-31 |
| Lessee, Operating Lease, Liability, to be Paid, Year Three | 58.00M | as of 2025-12-31 |
| Lessee, Operating Lease, Liability, to be Paid, Year Four | 43.00M | as of 2025-12-31 |
| Lessee, Operating Lease, Liability, to be Paid, Year Five | 29.00M | as of 2025-12-31 |
| Lessee, Operating Lease, Liability, to be Paid, after Year Five | 85.00M | as of 2025-12-31 |
| Utilities Operating Expense, Purchased Power | 4.58B | 2025-01-01 → 2025-12-31 |
| Lessee, Operating Lease, Liability, to be Paid | 348.00M | as of 2025-12-31 |
| Deferred Tax Assets, Other | 355.00M | as of 2025-12-31 |
| Utilities Operating Expense, Taxes | 1.34B | 2025-01-01 → 2025-12-31 |
| Lessee, Operating Lease, Liability, Undiscounted Excess Amount | 61.00M | as of 2025-12-31 |
| Excise Taxes Collected | 463.00M | 2025-01-01 → 2025-12-31 |
| Assets, Fair Value Disclosure | 458.00M | as of 2025-12-31 |
| Deferred Tax Liabilities, Regulatory Assets and Liabilities | 732.00M | as of 2025-12-31 |
| Financial and Nonfinancial Liabilities, Fair Value Disclosure | 1.00M | as of 2025-12-31 |
| Deferred Tax Liabilities, Parent's Basis in Discontinued Operation | 6.58B | as of 2025-12-31 |
| Deferred Tax Liabilities, Net | 6.03B | as of 2025-12-31 |
| Long-Term Debt, Maturity, Year One | 720.00M | as of 2025-12-31 |
| Long-Term Debt, Maturity, Year Two | 2.00B | as of 2025-12-31 |
| Long-Term Debt, Maturity, Year Three | 2.45B | as of 2025-12-31 |
| Long-Term Debt, Maturity, Year Four | 3.06B | as of 2025-12-31 |
| Long-Term Debt, Maturity, Year Five | 2.46B | as of 2025-12-31 |
| Debt Instrument, Unamortized Discount (Premium), Net | 20.00M | as of 2025-12-31 |
| Debt Issuance Costs, Gross | 150.00M | as of 2025-12-31 |
| Unrecognized Tax Benefits | 105.00M | as of 2025-12-31 |
| Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions | 0 | 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, Reduction Resulting from Lapse of Applicable Statute of Limitations | 0 | 2025-01-01 → 2025-12-31 |
| Pension and Other Postretirement Benefits Cost (Reversal of Cost) | 14.00M | 2025-01-01 → 2025-12-31 |
| Other Receivables | 295.00M | as of 2025-12-31 |
| Interest Costs Capitalized | 77.00M | 2025-01-01 → 2025-12-31 |