ASSET RETIREMENT OBLIGATIONS - Schedule of Changes to the ARO Balances (Details) - USD ($) $ in Millions |
3 Months Ended | 12 Months Ended |
|---|---|---|
Mar. 31, 2025 |
Dec. 31, 2024 |
|
| Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
| Beginning balance | $ 455 | $ 209 |
| Changes in timing and amount of estimated cash flows | 131 | |
| Liabilities incurred | 95 | |
| Liabilities settled | (151) | (4) |
| Accretion | 7 | 24 |
| Ending balance | 311 | 455 |
| JERSEY CENTRAL POWER & LIGHT COMPANY | ||
| Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
| Beginning balance | 8 | 7 |
| Changes in timing and amount of estimated cash flows | 0 | |
| Liabilities incurred | 0 | |
| Liabilities settled | 0 | 0 |
| Accretion | 0 | 1 |
| Ending balance | $ 8 | $ 8 |