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Reportable Segments - Schedule of Interest Income and Expenditures for Long-Lived Assets (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Houston Electric |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Interest income | $ 1 | $ 3 | $ 10 | $ 14
CERC |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Interest income | $ 0 | $ 1 | $ 10 | $ 2

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- Definition Amount of interest income earned from interest bearing assets classified as other. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 220 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 21 -Publisher FASB -URI https://asc.fasb.org/1943274/2147476153/220-40-55-21 + Details
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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. + References No definition available. + Details
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- Details
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- Details
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