Financing (Tables)

9 Months Ended

Sep. 30, 2021

Debt Disclosure [Abstract]

Schedule of Credit Arrangements

At September 30, 2021, committed credit arrangements with banks were as follows:

	Expires
Company	2022		2023		2024		2026		Total		Unused		Due within One Year
	(in millions)
Southern Company parent	$	—	$	—	$	—	$	2,000	$	2,000	$	1,999	$	—
Alabama Power	—		—		550		700		1,250		1,250		—
Georgia Power	—		—		—		1,750		1,750		1,726		—
Mississippi Power	—		125		150		—		275		250		—
Southern Power(a)	—		—		—		600		600		568		—
Southern Company Gas(b)	250		—		—		1,500		1,750		1,747		250
SEGCO	30		—		—		—		30		30		30
Southern Company	$	280	$	125	$	700	$	6,550	$	7,655	$	7,570	$	280

(a)Does not include Southern Power Company's $75 million and $60 million continuing letter of credit facilities for standby letters of credit expiring in 2023, of which $23 million and $1 million, respectively, was unused at September 30, 2021. Southern Power's subsidiaries are not parties to its bank credit arrangements or letter of credit facilities.

(b)Southern Company Gas, as the parent entity, guarantees the obligations of Southern Company Gas Capital, which is the borrower of $800 million of the arrangement expiring in 2026 and all $250 million of the arrangement expiring in 2022. Southern Company Gas' committed credit arrangement expiring in 2026 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 2026, the allocations between Southern Company Gas Capital and Nicor Gas may be adjusted.

Schedule of Shares Used to Compute Diluted Earnings Per Share

Shares used to compute diluted earnings per share were as follows:

	Three Months Ended September 30,		Nine Months Ended September 30,
	2021	2020	2021	2020
	(in millions)
As reported shares	1,061	1,058	1,060	1,058
Effect of stock-based compensation	7	6	7	6
Diluted shares	1,068	1,064	1,067	1,064