Retirement Benefits (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Pension Plans [Member] | Southern Company [Member]
Pension Plans and Postretirement Plans
Service cost	$ 54	$ 58	$ 107	$ 116
Interest cost	108	97	217	194
Expected return on plan assets	(162)	(150)	(323)	(301)
Amortization:
Prior service costs	7	6	13	13
Net (gain)/loss	27	50	55	100
Net cost	34	61	69	122
Pension Plans [Member] | Alabama Power [Member]
Pension Plans and Postretirement Plans
Service cost	12	14	24	27
Interest cost	26	23	52	46
Expected return on plan assets	(42)	(39)	(84)	(78)
Amortization:
Prior service costs	2	1	3	3
Net (gain)/loss	8	13	16	26
Net cost	6	12	11	24
Pension Plans [Member] | Georgia Power [Member]
Pension Plans and Postretirement Plans
Service cost	15	18	31	35
Interest cost	38	35	76	69
Expected return on plan assets	(56)	(53)	(113)	(106)
Amortization:
Prior service costs	2	2	5	5
Net (gain)/loss	10	18	20	37
Net cost	9	20	19	40
Pension Plans [Member] | Gulf Power [Member]
Pension Plans and Postretirement Plans
Service cost	1	2	4	5
Interest cost	5	5	10	9
Expected return on plan assets	(7)	(7)	(14)	(13)
Amortization:
Prior service costs	1	1	1	1
Net (gain)/loss	1	2	2	4
Net cost	1	3	3	6
Pension Plans [Member] | Mississippi Power [Member]
Pension Plans and Postretirement Plans
Service cost	2	2	5	5
Interest cost	5	4	10	9
Expected return on plan assets	(7)	(6)	(14)	(13)
Amortization:
Prior service costs	1	0	1	0
Net (gain)/loss	1	3	2	5
Net cost	2	3	4	6
Other Postretirement Benefits [Member] | Southern Company [Member]
Pension Plans and Postretirement Plans
Service cost	6	6	11	12
Interest cost	20	18	40	37
Expected return on plan assets	(15)	(14)	(30)	(28)
Amortization:
Transition obligation		1		2
Prior service costs	1	1	2	2
Net (gain)/loss	0	3	1	6
Net cost	12	15	24	31
Other Postretirement Benefits [Member] | Alabama Power [Member]
Pension Plans and Postretirement Plans
Service cost	2	1	3	3
Interest cost	5	4	10	9
Expected return on plan assets	(7)	(6)	(13)	(12)
Amortization:
Transition obligation		0		0
Prior service costs	1	1	2	2
Net (gain)/loss	0	1	0	1
Net cost	1	1	2	3
Other Postretirement Benefits [Member] | Georgia Power [Member]
Pension Plans and Postretirement Plans
Service cost	1	1	3	3
Interest cost	9	8	17	16
Expected return on plan assets	(7)	(6)	(13)	(12)
Amortization:
Transition obligation		1		2
Prior service costs	0	0	0	0
Net (gain)/loss	1	2	1	4
Net cost	4	6	8	13
Other Postretirement Benefits [Member] | Gulf Power [Member]
Pension Plans and Postretirement Plans
Service cost	1	1	1	1
Interest cost	1	0	2	1
Expected return on plan assets	(1)	0	(1)	0
Amortization:
Transition obligation		0		0
Prior service costs	0	0	0	0
Net (gain)/loss	0	0	0	0
Net cost	1	1	2	2
Other Postretirement Benefits [Member] | Mississippi Power [Member]
Pension Plans and Postretirement Plans
Service cost	1	1	1	1
Interest cost	1	1	2	2
Expected return on plan assets	(1)	(1)	(1)	(1)
Amortization:
Transition obligation		0		0
Prior service costs	0	0	0	0
Net (gain)/loss	0	0	0	0
Net cost	$ 1	$ 1	$ 2	$ 2