FINANCING - Bank Credit Arrangements (Details) - USD ($)	Feb. 16, 2022	Dec. 31, 2021
Line of Credit Facility [Line Items]
Expires, 2022		$ 280,000,000
Expires, 2023		125,000,000
Expires, 2024		700,000,000
Expires, 2025		6,550,000,000
Total		7,655,000,000
Unused		7,594,000,000
Due within One Year		280,000,000
Southern Company
Line of Credit Facility [Line Items]
Expires, 2022		0
Expires, 2023		0
Expires, 2024		0
Expires, 2025		2,000,000,000
Total		2,000,000,000
Unused		1,998,000,000
Due within One Year		0
Alabama Power
Line of Credit Facility [Line Items]
Expires, 2022		0
Expires, 2023		0
Expires, 2024		550,000,000
Expires, 2025		700,000,000
Total		1,250,000,000
Unused		1,250,000,000
Due within One Year		0
Georgia Power
Line of Credit Facility [Line Items]
Expires, 2022		0
Expires, 2023		0
Expires, 2024		0
Expires, 2025		1,750,000,000
Total		1,750,000,000
Unused		1,726,000,000
Due within One Year		0
Mississippi Power
Line of Credit Facility [Line Items]
Expires, 2022		0
Expires, 2023		125,000,000
Expires, 2024		150,000,000
Expires, 2025		0
Total		275,000,000
Unused		275,000,000
Due within One Year		0
Southern Power
Line of Credit Facility [Line Items]
Expires, 2022		0
Expires, 2023		0
Expires, 2024		0
Expires, 2025		600,000,000
Total		600,000,000
Unused		568,000,000
Due within One Year		0
Southern Power \| Continuing Letter of Credit Facility A
Line of Credit Facility [Line Items]
Expires, 2024		75,000,000
Unused		8,000,000
Southern Power \| Continuing Letter of Credit Facility B
Line of Credit Facility [Line Items]
Expires, 2024		60,000,000
Unused		4,000,000
Southern Power \| Continuing Letter of Credit Facility B \| Subsequent Event
Line of Credit Facility [Line Items]
Expires, 2025	$ 75,000,000
Southern Company Gas
Line of Credit Facility [Line Items]
Expires, 2022		250,000,000
Expires, 2023		0
Expires, 2024		0
Expires, 2025		1,500,000,000
Total		1,750,000,000
Unused		1,747,000,000
Due within One Year		250,000,000
Other Subsidiaries
Line of Credit Facility [Line Items]
Expires, 2022		30,000,000
Expires, 2023		0
Expires, 2024		0
Expires, 2025		0
Total		30,000,000
Unused		30,000,000
Due within One Year		30,000,000
Southern Company Gas Capital
Line of Credit Facility [Line Items]
Total		800,000,000
Nicor Gas
Line of Credit Facility [Line Items]
Total		$ 700,000,000

Bank credit arrangements no term loan due with in one year.

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- Definition

Line Of Credit Expire Year Four

+ References

No definition available.

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- Definition

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+ References

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- Definition

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- Definition

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+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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