Borrowings and Other Financing Instruments - Commercial Paper (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Jun. 30, 2026	Dec. 31, 2025
Short-term Debt [Line Items]
Short-term debt	$ 45	$ 220
Commercial Paper
Short-term Debt [Line Items]
Borrowing limit	600	600
Short-term debt	45	220
Average amount outstanding	111	97
Maximum amount outstanding	$ 195	$ 314
Weighted average interest rate, computed on a daily basis	4.08%	4.51%
Weighted average interest rate at period end	4.10%	3.93%

The effective interest rate during the reporting period.

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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.

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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.

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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.

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Weighted average interest rate of short-term debt outstanding calculated at point in time.

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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.

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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.

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No definition available.

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