Retirement Benefits (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Alabama Power [Member] | Pension Plans [Member]
Pension Plans and Postretirement Plans
Service cost	$ 10	$ 11	$ 21	$ 21
Interest cost	24	24	48	48
Expected return on plan assets	(43)	(42)	(86)	(84)
Net amortization	4	2	7	5
Net cost (income)	(5)	(5)	(10)	(10)
Alabama Power [Member] | Postretirement Benefits [Member]
Pension Plans and Postretirement Plans
Service cost	2	1	3	3
Interest cost	6	7	12	13
Expected return on plan assets	(7)	(6)	(13)	(12)
Net amortization	1	1	3	3
Net cost (income)	2	3	5	7
Georgia Power [Member] | Pension Plans [Member]
Pension Plans and Postretirement Plans
Service cost	15	13	29	27
Interest cost	36	37	72	73
Expected return on plan assets	(58)	(55)	(117)	(110)
Net amortization	4	3	9	7
Net cost (income)	(3)	(2)	(7)	(3)
Georgia Power [Member] | Postretirement Benefits [Member]
Pension Plans and Postretirement Plans
Service cost	2	2	4	4
Interest cost	10	11	20	22
Expected return on plan assets	(7)	(7)	(15)	(15)
Net amortization	2	3	5	6
Net cost (income)	7	9	14	17
Gulf Power [Member] | Pension Plans [Member]
Pension Plans and Postretirement Plans
Service cost	2	2	4	4
Interest cost	5	4	9	8
Expected return on plan assets	(7)	(6)	(14)	(12)
Net amortization			1	1
Net cost (income)	0	0	0	1
Gulf Power [Member] | Postretirement Benefits [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)
Net cost (income)	1	1	2	2
Mississippi Power [Member] | Pension Plans [Member]
Pension Plans and Postretirement Plans
Service cost	2	2	4	4
Interest cost	5	5	9	9
Expected return on plan assets	(6)	(6)	(12)	(11)
Net amortization			1	1
Net cost (income)	1	1	2	3
Mississippi Power [Member] | Postretirement Benefits [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)
Net cost (income)	1	1	2	2
Pension Plans [Member]
Pension Plans and Postretirement Plans
Service cost	46	43	92	86
Interest cost	97	97	195	195
Expected return on plan assets	(152)	(137)	(304)	(275)
Net amortization	13	10	26	21
Net cost (income)	4	13	9	27
Postretirement Benefits [Member]
Pension Plans and Postretirement Plans
Service cost	5	7	10	13
Interest cost	23	25	46	50
Expected return on plan assets	(16)	(16)	(32)	(32)
Net amortization	5	5	10	10
Net cost (income)	$ 17	$ 21	$ 34	$ 41