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REGULATORY MATTERS - GPC Schedule of Nuclear Construction Cost and Schedule (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2021 | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Commitments [Line Items] |  |  |  |
Total AFUDC and interest capitalized |  | $ 282 | $ 230 | $ 202
Georgia Power |  |  |  |
Commitments [Line Items] |  |  |  |
Total AFUDC and interest capitalized |  | 190 | $ 138 | $ 103
Pre-tax charge to income | $ 440 |  |  |
Georgia Power | Plant Vogtle Units 3 and 4 |  |  |  |
Commitments [Line Items] |  |  |  |
Base project capital cost forecast | 10,251 | 10,251 |  |
Construction contingency estimate | 150 | 150 |  |
Total project capital cost forecast | 10,401 | 10,401 |  |
Net investment | (8,442) | (8,442) |  |
Remaining estimate to complete | 1,959 | 1,959 |  |
Estimated cost to complete, costs not shared with other owners | 590 | 590 |  |
Total AFUDC and interest capitalized |  | 375 |  |
Total AFUDC and interest capitalized, accrual amount | $ 195 | $ 195 |  |

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- Definition Amount capitalized of allowance for funds used during construction. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 835 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6501569&loc=d3e55921-110430 + Details
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