Borrowings and Other Financing Instruments - Short-Term Borrowings (Details) - USD ($) $ in Millions |
3 Months Ended | 12 Months Ended |
|---|---|---|
Jun. 30, 2026 |
Dec. 31, 2025 |
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| Short-term Debt [Line Items] | ||
| Short-term debt | $ 0 | $ 260 |
| Money Pool | ||
| Short-term Debt [Line Items] | ||
| Borrowing limit | 250 | 250 |
| Short-term debt | 0 | 27 |
| Average amount outstanding | 2 | 37 |
| Maximum amount outstanding | $ 50 | $ 250 |
| Weighted average interest rate, computed on a daily basis (percentage) | 3.65% | 4.31% |
| Short-term Debt, Weighted Average Interest Rate, at Point in Time | 3.88% | |
| Commercial Paper | ||
| Short-term Debt [Line Items] | ||
| Borrowing limit | $ 1,200 | $ 1,200 |
| Short-term debt | 0 | 260 |
| Average amount outstanding | 2 | 106 |
| Maximum amount outstanding | $ 40 | $ 725 |
| Weighted average interest rate, computed on a daily basis (percentage) | 3.89% | 4.25% |
| Short-term Debt, Weighted Average Interest Rate, at Point in Time | 3.89% |
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- Definition The effective interest rate during the reporting period. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Weighted average interest rate of short-term debt outstanding calculated at point in time. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition For the form of debt having an initial term of less than one year or less than the normal operating cycle, if longer, average borrowings during the period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition For the form of debt having an initial term of less than one year or less than the normal operating cycle, if longer, the maximum amount borrowed at any time during the period. No definition available.
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