Regulatory Matters - Schedule of Allowed Equity Return (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
Dec. 31, 2024 |
|
| Public Utilities, General Disclosures [Line Items] | |||||
| Unrecognized equity return | $ 296 | $ 296 | $ 251 | ||
| Allowed equity return recognized | 7 | $ 12 | 9 | $ 21 | |
| Houston Electric | |||||
| Public Utilities, General Disclosures [Line Items] | |||||
| Unrecognized equity return | 131 | 131 | 94 | ||
| Allowed equity return recognized | 5 | 11 | 6 | 19 | |
| CERC | |||||
| Public Utilities, General Disclosures [Line Items] | |||||
| Unrecognized equity return | 101 | 101 | $ 92 | ||
| Allowed equity return recognized | $ 1 | $ 0 | $ 2 | $ 1 | |