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v3.25.3

FAIR VALUE MEASUREMENTS - Narrative (Details) $ / shares in Units, $ in Millions |  |  | 1 Months Ended | 3 Months Ended | 9 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Oct. 16, 2025 USD ($) | Jun. 12, 2025 USD ($) tradingDay consecutiveTradingDay $ / shares | Jun. 30, 2025 USD ($) | Sep. 30, 2025 USD ($) $ / shares | Sep. 30, 2024 USD ($) | Sep. 30, 2025 USD ($) $ / shares | Sep. 30, 2024 USD ($) | Sep. 04, 2025 USD ($) | Aug. 13, 2025 USD ($) | Dec. 31, 2024 USD ($) | Dec. 05, 2024 USD ($)
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Investments not required to be disclosed |  |  |  | $ 342 |  | $ 342 |  |  |  | $ 370 |
Repayments of debt |  |  |  |  |  | 2,179 | $ 1,710 |  |  |  |
Long-term debt |  |  |  |  |  | 5,925 | 1,200 |  |  |  |
JERSEY CENTRAL POWER & LIGHT COMPANY |  |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Repayments of debt |  |  |  |  |  | 0 | 500 |  |  |  |
Long-term debt |  |  |  |  |  | $ 1,350 | 0 |  |  |  |
Senior Unsecured Convertible Notes | 3.625%, Convertible Notes Maturity 2029 |  |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  | $ 1,350 |  |  |  |  |  |  |  |  |
Senior Unsecured Convertible Notes | 3.875%, Convertible Notes Maturity 2031 |  |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  | $ 1,150 |  |  |  |  |  |  |  |  |
Senior Unsecured Convertible Notes | Convertible Notes Maturity 2029 |  |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Issuance interest rate |  | 3.625% |  |  |  |  |  |  |  |  |
Senior Unsecured Convertible Notes | Convertible Notes Maturity 2031 |  |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Issuance interest rate |  | 3.875% |  |  |  |  |  |  |  |  |
Senior Unsecured Convertible Notes | Convertible Notes Maturity 2029 & 2031 |  |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Proceeds from issuance of debt |  | $ 2,470 |  |  |  |  |  |  |  |  |
Debt instrument, convertible, conversion ratio |  | 0.0209275 |  |  |  |  |  |  |  |  |
Debt instrument, conversion price (in dollars per share) | $ / shares |  | $ 47.78 |  |  |  |  |  |  |  |  |
Debt instrument convertible premium |  | 20.00% |  |  |  |  |  |  |  |  |
Redemption price, percentage |  | 100.00% |  |  |  |  |  |  |  |  |
Senior Unsecured Convertible Notes | Convertible Notes Maturity 2029 & 2031 | Debt Conversion Terms One |  |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument, convertible, threshold trading days | tradingDay |  | 20 |  |  |  |  |  |  |  |  |
Debt instrument, convertible, threshold consecutive trading days | tradingDay |  | 30 |  |  |  |  |  |  |  |  |
Debt instrument, convertible, threshold percentage of stock price trigger |  | 130.00% |  |  |  |  |  |  |  |  |
Senior Unsecured Convertible Notes | Convertible Notes Maturity 2029 & 2031 | Debt Conversion Terms Two |  |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument, convertible, threshold trading days | consecutiveTradingDay |  | 5 |  |  |  |  |  |  |  |  |
Debt instrument, convertible, threshold consecutive trading days | consecutiveTradingDay |  | 10 |  |  |  |  |  |  |  |  |
Threshold trading days measurement period | tradingDay |  | 10 |  |  |  |  |  |  |  |  |
Debt instrument, measurement period percentage |  | 98.00% |  |  |  |  |  |  |  |  |
Senior Unsecured Convertible Notes | Convertible Notes 2026 |  |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument, conversion price (in dollars per share) | $ / shares |  |  |  | $ 46.48 |  | $ 46.48 |  |  |  |  |
Repayments of debt |  |  | $ 1,200 |  |  |  |  |  |  |  |
Unsecured Debt | 4.75%, $450 Million Notes Maturity 2033 |  |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  | $ 450 |  |
Unsecured Debt | JERSEY CENTRAL POWER & LIGHT COMPANY | Senior Notes Maturity 2035 |  |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  |  |  | $ 700
Unsecured Debt | JERSEY CENTRAL POWER & LIGHT COMPANY | Unsecured Senior Notes Due 2029 |  |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  | $ 350 |  |  |
Unsecured Debt | JERSEY CENTRAL POWER & LIGHT COMPANY | Unsecured Senior Notes Due 2031 |  |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  | 500 |  |  |
Unsecured Debt | JERSEY CENTRAL POWER & LIGHT COMPANY | Unsecured Senior Notes Due 2036 |  |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  | $ 500 |  |  |
Unsecured Debt | JERSEY CENTRAL POWER & LIGHT COMPANY | Unsecured Senior Notes Due 2026 | Subsequent Event |  |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Issuance interest rate | 4.30% |  |  |  |  |  |  |  |  |  |
Repayments of debt | $ 650 |  |  |  |  |  |  |  |  |  |
Corporate-Owned Life Insurance |  |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Gain on investments |  |  |  | $ 8 | $ 10 | $ 17 | $ 20 |  |  |  |

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