STOCK COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Schedule of employees participating in stock-based compensation programs

At December 31, 2020, the number of current and former employees participating in stock-based compensation programs for the Registrants was as follows:

	Southern Company	Alabama Power	Georgia Power	Mississippi Power	Southern Power	Southern Company Gas
Number of employees	1,958	263	295	86	46	204

Assumptions used in the pricing model and the weighted average grant-date fair value of performance share award units granted

The following table shows the assumptions used in the pricing model and the weighted average grant-date fair value of TSR awards granted:

Year Ended December 31	2020	2019	2018
Expected volatility	15.4%	15.6%	14.9%
Expected term (in years)	3	3	3
Interest rate	1.4%	2.4%	2.4%
Weighted average grant-date fair value	$77.65	$62.71	$43.75

Schedule of compensation costs and related tax benefits

Total PSU compensation cost, and the related tax benefit recognized in income, for the years ended December 31, 2020, 2019, and 2018 are as follows:

	2020		2019		2018
	(in millions)
Southern Company
Compensation cost recognized in income	$	84	$	77	$	91
Tax benefit of compensation cost recognized in income	22		20		24
Southern Company Gas
Compensation cost recognized in income	$	13	$	14	$	11
Tax benefit of compensation cost recognized in income	4		4		3

Total intrinsic value of options exercised, and the related tax benefit, for the years ended December 31, 2020, 2019, and 2018 are presented below:

Year Ended December 31	2020		2019		2018
	(in millions)
Southern Company
Intrinsic value of options exercised	$	38	$	167	$	9
Tax benefit of options exercised	9		35		2
Alabama Power
Intrinsic value of options exercised	$	5	$	21	$	2
Tax benefit of options exercised	1		4		—
Georgia Power
Intrinsic value of options exercised	$	9	$	30	$	2
Tax benefit of options exercised	2		6		—

Share-based compensation, stock options, activity

Southern Company's activity in the stock option program for 2020 is summarized below:

	Shares Subject to Option	Weighted Average Exercise Price
	(in millions)
Outstanding at December 31, 2019	5.9	$	42.52
Exercised	1.6	41.13
Outstanding and Exercisable at December 31, 2020	4.3	$	43.04

Schedule of aggregate and total intrinsic value of options exercised

At December 31, 2020, the aggregate intrinsic value for the options outstanding and exercisable was as follows:

	Southern Company		Alabama Power		Georgia Power		Southern Company Gas
	(in millions)
Total intrinsic value for outstanding and exercisable options	$	78	$	8	$	25	$	6