Equity Securities and Indexed Debt Securities (ZENS) (CenterPoint Energy) - Schedule of Securities Classified as Trading (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Debt and Equity Securities, FV-NI [Line Items]
Carrying Value	$ 683	$ 561
AT&T Common
Debt and Equity Securities, FV-NI [Line Items]
Balance of investment owned (in shares)	10,212,945	10,212,945
Carrying Value	$ 296	$ 233
Charter Common
Debt and Equity Securities, FV-NI [Line Items]
Balance of investment owned (in shares)	872,503	872,503
Carrying Value	$ 356	$ 299
WBD Common
Debt and Equity Securities, FV-NI [Line Items]
Balance of investment owned (in shares)	2,470,685	2,470,685
Carrying Value	$ 28	$ 26
Other
Debt and Equity Securities, FV-NI [Line Items]
Carrying Value	$ 3	$ 3

Fair value of investment in security owned.

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+ Details