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Consolidated Statements of Cash Flows - GAS (Parenthetical) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Net cash paid for capitalized interest | $ 92 | $ 81 | $ 74
Southern Company Gas |  |  |
Net cash paid for capitalized interest | $ 8 | $ 7 | $ 6

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