STOCK COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2019

Equity [Abstract]

Schedule of employees participating in stock-based compensation programs

At December 31, 2019, 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	2,320	307	370	89	50	285

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	2019	2018	2017
Expected volatility	15.6%	14.9%	15.6%
Expected term (in years)	3	3	3
Interest rate	2.4%	2.4%	1.4%
Weighted average grant-date fair value	$62.71	$43.75	$49.08

Schedule of compensation costs and related tax benefits

Total intrinsic value of options exercised, and the related tax benefit, for the years ended December 31, 2019, 2018, and 2017 are presented below:

Year Ended December 31	2019		2018		2017
	(in millions)
Southern Company
Intrinsic value of options exercised	$	167	$	9	$	64
Tax benefit of options exercised	35		2		25
Alabama Power
Intrinsic value of options exercised	$	21	$	2	$	12
Tax benefit of options exercised	4		—		5
Georgia Power
Intrinsic value of options exercised	$	30	$	2	$	13
Tax benefit of options exercised	6		—		5
Mississippi Power
Intrinsic value of options exercised	$	4	$	1	$	2
Tax benefit of options exercised	1		—		1

Total PSU compensation cost, and the related tax benefit recognized in income, for the years ended December 31, 2019, 2018, and 2017 are as follows:

	2019		2018		2017
	(in millions)
Southern Company
Compensation cost recognized in income	$	77	$	91	$	74
Tax benefit of compensation cost recognized in income	20		24		29
Southern Company Gas
Compensation cost recognized in income	$	14	$	11	$	8
Tax benefit of compensation cost recognized in income	4		3		3

Share-based compensation, stock options, activity

Southern Company's activity in the stock option program for 2019 is summarized below:

	Shares Subject to Option	Weighted Average Exercise Price
	(in millions)
Outstanding at December 31, 2018	17.5	$	41.92
Exercised	11.6	41.62
Outstanding and Exercisable at December 31, 2019	5.9	$	42.52

Schedule of aggregate and total intrinsic value of options exercised

At December 31, 2019, the aggregate intrinsic value for the options outstanding and exercisable was as follows:

	Southern Company		Alabama Power		Georgia Power		Mississippi Power
	(in millions)
Total intrinsic value for outstanding and exercisable options	$	124	$	14	$	35	$	6