Equity Securities and Indexed Debt Securities (ZENS) (CenterPoint Energy) - Schedule of Gain (Loss) On Equity Securities (CenterPoint Energy) (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2025 |
Sep. 30, 2024 |
Sep. 30, 2025 |
Sep. 30, 2024 |
|
| Debt and Equity Securities, FV-NI [Line Items] | ||||
| Total gains (losses) on equity securities, net | $ (104) | $ 54 | $ 18 | $ (10) |
| AT&T Common | ||||
| Debt and Equity Securities, FV-NI [Line Items] | ||||
| Total gains (losses) on equity securities, net | (8) | 29 | 55 | 53 |
| Charter Common | ||||
| Debt and Equity Securities, FV-NI [Line Items] | ||||
| Total gains (losses) on equity securities, net | (116) | 22 | (59) | (56) |
| WBD Common | ||||
| Debt and Equity Securities, FV-NI [Line Items] | ||||
| Total gains (losses) on equity securities, net | $ 20 | $ 3 | $ 22 | $ (7) |