Related Party Transactions - Schedule of Money Pool Activity (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Houston Electric
Related Party Transaction [Line Items]
Money pool investments (borrowings)	$ 764	$ (54)
Houston Electric \| Investments
Related Party Transaction [Line Items]
Weighted average interest rate	3.74%	3.83%
CERC
Related Party Transaction [Line Items]
Money pool investments (borrowings)	$ (345)	$ (291)
CERC \| Investments
Related Party Transaction [Line Items]
Weighted average interest rate	3.74%	3.83%

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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+ Details