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Regulatory Matters - GPC Rate Plans (Details) $ in Millions |  |  |  |  |  |  |  |  | 1 Months Ended | 9 Months Ended
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Sep. 17, 2025 MW | Sep. 04, 2025 MW | Jul. 30, 2025 project MW unit | Jul. 15, 2025 USD ($) MW facility | Jul. 08, 2025 MW | Jul. 01, 2025 | May 14, 2025 USD ($) | Apr. 01, 2025 USD ($) | Jul. 31, 2025 project MW | Jul. 30, 2025 USD ($) MW | Sep. 30, 2025 USD ($)
GEORGIA POWER CO |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Requested additional generating capacity (in MWs) |  | 200 |  |  |  |  |  |  | 1,100 |  |
Approximate nameplate capacity |  |  | 260 |  |  |  |  |  |  | 260 |
Requested rate increase amount | $ |  |  |  |  |  |  |  |  |  | $ 16,700 |
Capital costs | $ |  |  |  |  |  |  |  |  |  |  | $ 1,500
GEORGIA POWER CO | First PPA |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Approved capacity increase (in MWs) |  |  |  |  |  |  |  |  | 930 |  |
Life output of plant (in years) |  |  |  |  |  |  |  |  | 20 years |  |
GEORGIA POWER CO | Second PPA |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Approved capacity increase (in MWs) |  |  |  |  |  |  |  |  | 646 |  |
Number of PPAs | project |  |  |  |  |  |  |  |  | 5 |  |
Life output of plant (in years) |  |  |  |  |  |  |  |  | 25 years |  |
GEORGIA POWER CO | Affiliate PPA |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Requested additional generating capacity (in MWs) |  |  |  |  |  |  |  |  | 50 |  |
Approved capacity increase (in MWs) |  |  |  |  |  |  |  |  | 750 |  |
GEORGIA POWER CO | Project Group 1 |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Number of PPAs | project |  |  | 4 |  |  |  |  |  |  |  |
Public Utilities, Additional Generating Capacity To be Certified |  |  | 1,195 |  |  |  |  |  |  |  |
GEORGIA POWER CO | project Group 2 |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Number of projects | project |  |  | 3 |  |  |  |  |  |  |  |
Number of units | unit |  |  | 5 |  |  |  |  |  |  |  |
Public Utilities, Additional Generating Capacity To be Certified |  |  | 3,692 |  |  |  |  |  |  |  |
GEORGIA POWER CO | Project Group 3 |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Number of projects | project |  |  | 9 |  |  |  |  |  |  |  |
Public Utilities, Additional Generating Capacity To be Certified |  |  | 2,762 |  |  |  |  |  |  |  |
GEORGIA POWER CO | Fourth Project Group |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Number of projects | project |  |  | 2 |  |  |  |  |  |  |  |
Public Utilities, Additional Generating Capacity To be Certified |  |  | 350 |  |  |  |  |  |  |  |
GEORGIA POWER CO | July 2025 Requested For Certification |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Capital costs | $ |  |  |  |  |  |  |  |  |  |  | $ 725
GEORGIA POWER CO | SEGCO |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Requested additional generating capacity (in MWs) |  |  |  | 500 |  |  |  |  |  |  |
Ownership percentage, equity method investment |  |  |  | 50.00% |  |  |  |  |  |  |
GEORGIA POWER CO | Plant Scherer Unit Three |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Requested additional generating capacity (in MWs) |  |  |  | 614 |  |  |  |  |  |  |
Proportionate ownership share |  |  |  | 75.00% |  |  |  |  |  |  |
GEORGIA POWER CO | Plant Bowen Units 1 Through 4 |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Requested additional generating capacity (in MWs) |  |  |  | 3,160 |  |  |  |  |  |  |
GEORGIA POWER CO | Plant Scherer Coal Units One and Two |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Requested additional generating capacity (in MWs) |  |  |  | 137 |  |  |  |  |  |  |
Proportionate ownership share |  |  |  | 8.40% |  |  |  |  |  |  |
GEORGIA POWER CO | Plant McIntosh Units 10 And 11 |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Requested additional generating capacity (in MWs) |  |  |  | 1,319 |  |  |  |  |  |  |
Additional capacity |  |  |  | 194 |  |  |  |  |  |  |
GEORGIA POWER CO | Plant McIntosh Units 1 Through 8 |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Requested additional generating capacity (in MWs) |  |  |  | 640 |  |  |  |  |  |  |
Additional capacity |  |  |  | 74 |  |  |  |  |  |  |
GEORGIA POWER CO | Plant Vogtle Nuclear Units One and Two |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Requested additional generating capacity (in MWs) |  |  |  | 1,060 |  |  |  |  |  |  |
Proportionate ownership share |  |  |  | 45.70% |  |  |  |  |  |  |
Additional capacity |  |  |  | 54 |  |  |  |  |  |  |
GEORGIA POWER CO | Plant Scherer Unit 3 |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Requested additional generating capacity (in MWs) |  |  |  |  |  |  |  |  | 187 |  |
GEORGIA POWER CO | Hydro Operations |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Approved rate increase (decrease) | $ |  |  |  | $ 25 |  |  |  |  |  |  |
Number of facilities | facility |  |  |  | 4 |  |  |  |  |  |  |
Number of additional facilities | facility |  |  |  | 2 |  |  |  |  |  |  |
GEORGIA POWER CO | Maximum |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Requested additional generating capacity (in MWs) | 8,500 |  |  |  |  |  |  |  |  |  |
Approved rate increase (decrease) | $ |  |  |  |  |  |  | $ 200 |  |  |  |
Number of projects | project |  |  | 18 |  |  |  |  |  |  |  |
Number of affiliate PPAs | project |  |  | 2 |  |  |  |  |  |  |  |
Public Utilities, Additional Generating Capacity To be Certified |  |  | 7,999 |  |  |  |  |  |  |  |
GEORGIA POWER CO | 2022 Alternate Rate Plan |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Retail rate of return on common equity |  |  |  |  |  | 10.50% |  |  |  |  |
Equity rate of return on common equity |  |  |  |  |  | 56.00% |  |  |  |  |
Portion of actual earnings above approved ROE applied to regulatory assets |  |  |  |  |  | 40.00% |  |  |  |  |
Portion of actual earnings above approved ROE band refunded to customers |  |  |  |  |  | 40.00% |  |  |  |  |
Portion of actual earnings above approved ROE band retained by subsidiary company |  |  |  |  |  | 20.00% |  |  |  |  |
GEORGIA POWER CO | 2022 Alternate Rate Plan | Minimum |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Retail rate of return on common equity |  |  |  |  |  | 9.50% |  |  |  |  |
GEORGIA POWER CO | 2022 Alternate Rate Plan | Maximum |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Retail rate of return on common equity |  |  |  |  |  | 11.90% |  |  |  |  |
MISSISSIPPI POWER CO |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Approved rate increase (decrease) | $ |  |  |  |  |  |  |  | $ 8 |  |  |
MISSISSIPPI POWER CO | Affiliate PPA |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Requested additional generating capacity (in MWs) |  |  |  |  | 50 |  |  |  |  |  |
Approved capacity increase (in MWs) |  |  |  |  | 750 |  |  |  |  |  |

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