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Introduction - Schedule of Other Intangible Assets (Details) - USD ($) $ in Millions | Sep. 30, 2025 | Dec. 31, 2024
--- | --- | ---
Subject to amortization: |  |
Gross Carrying Amount | $ 669 | $ 669
Accumulated Amortization | (436) | (412)
Other Intangible Assets, Net | 233 | 257
Not subject to amortization: |  |
FCC licenses | 75 | 75
Total other intangible assets |  |
Gross Carrying Amount | 744 | 744
Accumulated Amortization | (436) | (412)
Other Intangible Assets, Net | 308 | 332
Customer relationships |  |
Subject to amortization: |  |
Gross Carrying Amount | 212 | 212
Accumulated Amortization | (186) | (182)
Other Intangible Assets, Net | 26 | 30
Total other intangible assets |  |
Accumulated Amortization | (186) | (182)
Trade names |  |
Subject to amortization: |  |
Gross Carrying Amount | 64 | 64
Accumulated Amortization | (64) | (59)
Other Intangible Assets, Net | 0 | 5
Total other intangible assets |  |
Accumulated Amortization | (64) | (59)
PPA fair value adjustments |  |
Subject to amortization: |  |
Gross Carrying Amount | 390 | 390
Accumulated Amortization | (183) | (168)
Other Intangible Assets, Net | 207 | 222
Total other intangible assets |  |
Accumulated Amortization | (183) | (168)
Other |  |
Subject to amortization: |  |
Gross Carrying Amount | 3 | 3
Accumulated Amortization | (3) | (3)
Other Intangible Assets, Net | 0 | 0
Total other intangible assets |  |
Accumulated Amortization | (3) | (3)
SOUTHERN POWER CO |  |
Subject to amortization: |  |
Accumulated Amortization | (183) | (168)
Total other intangible assets |  |
Accumulated Amortization | (183) | (168)
SOUTHERN POWER CO | PPA fair value adjustments |  |
Subject to amortization: |  |
Gross Carrying Amount | 390 | 390
Accumulated Amortization | (183) | (168)
Other Intangible Assets, Net | 207 | 222
Total other intangible assets |  |
Accumulated Amortization | (183) | (168)
SOUTHERN Co GAS |  |
Subject to amortization: |  |
Gross Carrying Amount | 182 | 182
Accumulated Amortization | (178) | (173)
Other Intangible Assets, Net | 4 | 9
Total other intangible assets |  |
Accumulated Amortization | (178) | (173)
Other Intangible Assets, Net | 4 | 9
SOUTHERN Co GAS | Customer relationships |  |
Subject to amortization: |  |
Gross Carrying Amount | 156 | 156
Accumulated Amortization | (152) | (150)
Other Intangible Assets, Net | 4 | 6
Total other intangible assets |  |
Accumulated Amortization | (152) | (150)
SOUTHERN Co GAS | Trade names |  |
Subject to amortization: |  |
Gross Carrying Amount | 26 | 26
Accumulated Amortization | (26) | (23)
Other Intangible Assets, Net | 0 | 3
Total other intangible assets |  |
Accumulated Amortization | $ (26) | $ (23)

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