Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net Income (Loss)	$ 2,435	$ 2,031	$ 1,710
Qualifying hedges:
Changes in fair value, net of tax	(13)	(10)	0
Reclassification adjustment for amounts included in net income, net of tax	6	5	9
Marketable securities:
Change in fair value, net of tax	0	0	(3)
Pension and other postretirement benefit plans:
Benefit plan net gain (loss),net of tax	(2)	(51)	36
Reclassification adjustment for amounts included in net income, net of tax	7	3	6
Total other comprehensive income (loss)	(2)	(53)	48
Dividends on preferred and preference stock of subsidiaries	54	68	66
Comprehensive income attributable to noncontrolling interests	14	0	0
Comprehensive Income	2,365	1,910	1,692
Alabama Power [Member]
Net Income (Loss)	811	800	751
Qualifying hedges:
Changes in fair value, net of tax	(5)	(5)	0
Reclassification adjustment for amounts included in net income, net of tax	2	2	1
Pension and other postretirement benefit plans:
Total other comprehensive income (loss)	(3)	(3)	1
Dividends on preferred and preference stock of subsidiaries	26	39	39
Comprehensive Income	808	797	752
Georgia Power [Member]
Net Income (Loss)	1,277	1,242	1,191
Qualifying hedges:
Changes in fair value, net of tax	(9)	(5)	0
Reclassification adjustment for amounts included in net income, net of tax	2	2	2
Pension and other postretirement benefit plans:
Total other comprehensive income (loss)	(7)	(3)	2
Dividends on preferred and preference stock of subsidiaries	17	17	17
Comprehensive Income	1,270	1,239	1,193
Gulf Power [Member]
Net Income (Loss)	157	149	132
Qualifying hedges:
Changes in fair value, net of tax	1	0	0
Reclassification adjustment for amounts included in net income, net of tax	0	0	1
Pension and other postretirement benefit plans:
Total other comprehensive income (loss)	1	0	1
Dividends on preferred and preference stock of subsidiaries	9	9	8
Comprehensive Income	158	149	133
Mississippi Power [Member]
Net Income (Loss)	(6)	(327)	(475)
Qualifying hedges:
Reclassification adjustment for amounts included in net income, net of tax	1	1	1
Pension and other postretirement benefit plans:
Total other comprehensive income (loss)	1	1	1
Dividends on preferred and preference stock of subsidiaries	2	2	2
Comprehensive Income	(5)	(326)	(474)
Southern Power [Member]
Net Income (Loss)	229	175	166
Qualifying hedges:
Reclassification adjustment for amounts included in net income, net of tax	1	0	4
Pension and other postretirement benefit plans:
Total other comprehensive income (loss)	1	0	4
Comprehensive income attributable to noncontrolling interests	14	3	0
Comprehensive Income	$ 216	$ 172	$ 170