FINANCING (Tables)

12 Months Ended

Dec. 31, 2023

Debt Disclosure [Abstract]

Summary of long-term debt

Details of long-term debt at December 31, 2023 and 2022 are provided in the following table:

	At December 31, 2023		Balance Outstanding at December 31,
	Maturity	Weighted Average Interest Rate	2023		2022
			(in millions)
Southern Company
Senior notes(a)	2024-2073	4.16%	$	40,235	$	35,683
Junior subordinated notes	2024-2081	4.33%	8,333		8,836
FFB loans(b)	2024-2044	2.88%	4,788		4,874
Revenue bonds(c)	2024-2063	3.77%	3,400		2,844
First mortgage bonds(d)	2025-2063	3.64%	2,500		2,275
Medium-term notes	2026-2027	7.03%	84		84
Other long-term debt	2024-2045	5.44%	234		167
Finance lease obligations(e)			298		314
Unamortized fair value adjustment			302		330
Unamortized debt premium (discount), net			(198)		(193)
Unamortized debt issuance expenses			(290)		(273)
Total long-term debt			59,686		54,941
Less: Amount due within one year			2,476		4,285
Total long-term debt excluding amount due within one year			$	57,210	$	50,656
Alabama Power
Senior notes	2025-2073	3.95%	$	9,875	$	9,675
Revenue bonds(c)	2024-2063	3.94%	1,321		995
Other long-term debt	2026-2030	7.04%	75		45
Finance lease obligations(e)			5		5
Unamortized debt premium (discount), net			(20)		(18)
Unamortized debt issuance expenses			(73)		(72)
Total long-term debt			11,183		10,630
Less: Amount due within one year			223		301
Total long-term debt excluding amount due within one year			$	10,960	$	10,329
Georgia Power
Senior notes	2024-2052	4.34%	$	9,575	$	7,925
Junior subordinated notes	2077	5.00%	270		270
FFB loans(b)	2024-2044	2.88%	4,788		4,874
Revenue bonds(c)	2025-2062	3.64%	1,968		1,738
Finance lease obligations(e)			240		238
Unamortized debt premium (discount), net			(19)		(18)
Unamortized debt issuance expenses			(122)		(117)
Total long-term debt			16,700		14,910
Less: Amount due within one year			502		901
Total long-term debt excluding amount due within one year			$	16,198	$	14,009

	At December 31, 2023		Balance Outstanding at December 31,
	Maturity	Weighted Average Interest Rate	2023		2022
			(in millions)
Mississippi Power
Senior notes	2024-2051	4.27%	$	1,525	$	1,425
Revenue bonds(c)	2025-2052	4.08%	111		111
Finance lease obligations(e)			16		17
Unamortized debt premium (discount), net			1		2
Unamortized debt issuance expenses			(9)		(10)
Total long-term debt			1,644		1,545
Less: Amount due within one year			201		1
Total long-term debt excluding amount due within one year			$	1,443	$	1,544
Southern Power
Senior notes(a)	2025-2046	4.05%	$	2,728	$	2,998
Unamortized debt premium (discount), net			(4)		(5)
Unamortized debt issuance expenses			(13)		(14)
Total long-term debt			2,711		2,979
Less: Amount due within one year			—		290
Total long-term debt excluding amount due within one year			$	2,711	$	2,689
Southern Company Gas
Senior notes	2025-2051	4.36%	$	4,930	$	4,769
First mortgage bonds(d)	2025-2063	3.64%	2,500		2,275
Medium-term notes	2026-2027	7.03%	84		84
Other long-term debt	2024-2045	3.81%	59		22
Unamortized fair value adjustment			302		330
Unamortized debt premium (discount), net			(8)		(8)
Unamortized debt issuance expenses			(34)		(30)
Total long-term debt			7,833		7,442
Less: Amount due within one year			—		400
Total long-term debt excluding amount due within one year			$	7,833	$	7,042

(a)Includes a fair value gain (loss) of $(12) million and $(31) million at December 31, 2023 and 2022, respectively, related to Southern Power's foreign currency hedge on its euro-denominated senior notes.

(b)Secured by a first priority lien on (i) Georgia Power's undivided ownership interest in Plant Vogtle Units 3 and 4 (primarily the units, the related real property, and any nuclear fuel loaded in the reactor core) and (ii) Georgia Power's rights and obligations under the principal contracts relating to Plant Vogtle Units 3 and 4. See "DOE Loan Guarantee Borrowings" herein for additional information.

(c)Revenue bond obligations represent loans to the traditional electric operating companies from public authorities of funds derived from sales by such authorities of revenue bonds issued to finance pollution control and solid waste disposal and wastewater facilities. In some cases, the revenue bond obligations represent obligations under installment sales agreements with respect to facilities constructed with the proceeds of revenue bonds issued by public authorities. The traditional electric operating companies are required to make payments sufficient for the authorities to meet principal and interest requirements of such bonds. Proceeds from certain issuances are restricted until qualifying expenditures are incurred.

(d)Secured by substantially all of Nicor Gas' properties.

(e)Secured by the underlying lease ROU asset. See Note 9 for additional information.

Schedule of maturities of long-term debt for the next five years

Maturities of long-term debt for the next five years are as follows:

	Southern Company(a)		Alabama Power(b)		Georgia Power(c)		Mississippi Power		Southern Power(d)		Southern Company Gas
	(in millions)
2024	$	2,480	$	223	$	503	$	201	$	—	$	—
2025	4,124		251		849		12		500		300
2026	3,791		46		448		66		964		530
2027	2,075		551		512		10		—		154
2028	2,612		107		864		357		—		150

(a)See notes (b) and (c) below.

(b)Alabama Power's 2024 maturities include $200 million aggregate principal amount of Series 2023A Floating Rate Senior Notes due May 15, 2073 that are repayable at the option of the holders at certain dates beginning in 2024. As a result, the senior notes are classified as securities due within one year on the balance sheets of Southern Company and Alabama Power at December 31, 2023.

(c)Amounts include principal amortization related to the FFB borrowings; however, the final maturity date is February 20, 2044. See "DOE Loan Guarantee Borrowings" herein for additional information.

(d)Southern Power's 2026 maturities include $564 million of euro-denominated debt at the U.S. dollar denominated hedge settlement amount.

Summary of committed credit arrangements

At December 31, 2023, committed credit arrangements with banks were as follows:

	Expires
Company	2024		2025		2026		2028		Total		Unused		Expires within One Year
	(in millions)
Southern Company parent(a)	$	150	$	—	$	—	$	1,850	$	2,000	$	1,998	$	150
Alabama Power	—		—		650		700		1,350		1,350		—
Georgia Power	—		—		—		1,750		1,750		1,726		—
Mississippi Power	—		125		150		—		275		275		—
Southern Power(a)(b)	—		—		—		600		600		589		—
Southern Company Gas(c)	100		—		—		1,500		1,600		1,598		100
SEGCO	30		—		—		—		30		30		30
Southern Company	$	280	$	125	$	800	$	6,400	$	7,605	$	7,566	$	280

(a)Arrangement expiring in 2028 represents a $2.45 billion combined arrangement for Southern Company and Southern Power as borrowers. Pursuant to the combined facility, the allocations between Southern Company and Southern Power may be adjusted.

(b)Does not include Southern Power Company's $75 million and $100 million continuing letter of credit facilities for standby letters of credit, expiring in 2025 and 2026, respectively, of which $8 million and $7 million, respectively, was unused at December 31, 2023. Southern Power's subsidiaries are not parties to its bank credit arrangements or letter of credit facilities.

(c)Southern Company Gas, as the parent entity, guarantees the obligations of Southern Company Gas Capital, which is the borrower of $800 million of the credit arrangement expiring in 2028. Southern Company Gas' committed credit arrangement expiring in 2028 also includes $700 million for which Nicor Gas is the borrower and which is restricted for working capital needs of Nicor Gas. Pursuant to the multi-year credit arrangement expiring in 2028, the allocations between Southern Company Gas Capital and Nicor Gas may be adjusted. Nicor Gas is also the borrower under a $100 million credit arrangement expiring in 2024. See "Structural Considerations" herein for additional information.

Details of short-term borrowings

Details of short-term borrowings for the applicable Registrants were as follows:

	Notes Payable at December 31, 2023				Notes Payable at December 31, 2022
	Amount Outstanding		Weighted Average Interest Rate		Amount Outstanding		Weighted Average Interest Rate
	(in millions)				(in millions)
Southern Company
Commercial paper	$	1,794	5.6	%	$	809	4.7	%
Short-term bank debt	520		6.4	%	1,800		5.0	%
Total	$	2,314	5.7	%	$	2,609	4.9	%
Alabama Power
Commercial paper	$	40	5.5	%	$	—	—	%
Georgia Power
Commercial paper	$	809	5.6	%	$	—	—	%
Short-term bank debt	520		6.4	%	1,600		5.0	%
Total	$	1,329	5.9	%	$	1,600	5.0	%
Southern Power
Commercial paper	$	138	5.5	%	$	225	4.7	%
Southern Company Gas
Commercial paper:
Southern Company Gas Capital	$	23	5.5	%	$	285	4.8	%
Nicor Gas	392		5.5	%	283		4.6	%
Short-term bank debt:
Nicor Gas	—		—	%	200		4.9	%
Total	$	415	5.5	%	$	768	4.7	%

Shares used to compute diluted EPS

Shares used to compute diluted EPS were as follows:

	Average Common Stock Shares
	2023	2022	2021
	(in millions)
As reported shares	1,092	1,075	1,061
Effect of stock-based compensation	6	6	7
Diluted shares	1,098	1,081	1,068

Schedule of preferred stock

Preferred Stock Redeemed During 2022	Par Value/Stated Capital Per Share	Shares	Redemption Price Per Share
4.92% Preferred Stock	$100	80,000	$103.23
4.72% Preferred Stock	$100	50,000	$102.18
4.64% Preferred Stock	$100	60,000	$103.14
4.60% Preferred Stock	$100	100,000	$104.20
4.52% Preferred Stock	$100	50,000	$102.93
4.20% Preferred Stock	$100	135,115	$105.00
5.00% Class A Preferred Stock	$25	10,000,000	$25.00