SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - (Financial Assets Measured at Amortized Cost – Credit Losses) (Narrative) (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
Dec. 31, 2025 |
|
| Public Utility, Property, Plant and Equipment [Line Items] | |||||
| Credit losses | $ 66 | $ 89 | $ 185 | $ 331 | |
| Regulatory assets | 16,531 | 16,531 | $ 15,981 | ||
| Regulatory Balancing Accounts Receivable | |||||
| Public Utility, Property, Plant and Equipment [Line Items] | |||||
| Total regulatory balancing accounts | 4,846 | 4,846 | 6,300 | ||
| FERC TO rates | |||||
| Public Utility, Property, Plant and Equipment [Line Items] | |||||
| Regulatory assets | 84 | 84 | 92 | ||
| Residential uncollectibles balancing accounts | Regulatory Balancing Accounts Receivable | |||||
| Public Utility, Property, Plant and Equipment [Line Items] | |||||
| Total regulatory balancing accounts | $ 162 | 162 | $ 278 | ||
| Decrease in regulatory balancing accounts | $ 278 | ||||