Condensed Consolidated Statements of Comprehensive Income (Unaudited) - GAS (Parenthetical) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Changes in fair value, tax	$ 3	$ 2	$ (11)	$ (5)
Qualifying hedges, reclassification adjustment, tax	12	8	25	32
SOUTHERN Co GAS
Changes in fair value, tax	(2)	8	(11)	16
Qualifying hedges, reclassification adjustment, tax	$ 7	$ (2)	$ 15	$ (7)

Amount of tax expense (benefit) for reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-12

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Data Type:	xbrli:monetaryItemType
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