Retirement Benefits (Tables)

6 Months Ended

Jun. 30, 2012

Retirement Benefits [Abstract]

Pension Plans and Postretirement Plans

Pension Plans	Southern Company	Alabama Power	Georgia Power	Gulf Power	Mississippi   Power
	(in millions)
Three Months Ended June 30, 2012
Service cost	$   49	$ 11	$ 15	$   3	$ 3
Interest cost	99	24	36	4	4
Expected return on plan assets	(146)	(41)	(55)	(7)	(6)
Net amortization	31	7	11	2	1
Net cost (income)	$   33	$   1	$7	$   2	$ 2
Six Months Ended June 30, 2012
Service cost	$   99	$ 22	$ 30	$   5	$  5
Interest cost	197	47	71	8	9
Expected return on plan assets	(291)	(81)	(110)	(13)	(12)
Net amortization	62	15	22	3	2
Net cost (income)	$  67	$   3	$ 13	$   3	$  4
Three Months Ended June 30, 2011
Service cost	$   46	$ 10	$ 15	$  2	$  2
Interest cost	97	24	36	5	5
Expected return on plan assets	(152)	(43)	(58)	(7)	(6)
Net amortization	13	4	4	—	—
Net cost (income)	$    4	$  (5)	$ (3)	$—	$  1
Six Months Ended June 30, 2011
Service cost	$    92	$  21	$  29	$  4	$  4
Interest cost	195	48	72	9	9
Expected return on plan assets	(304)	(86)	(117)	(14)	(12)
Net amortization	26	7	9	1	1
Net cost (income)	$     9	$ (10)	$  (7)	$ —	$  2

Postretirement Benefits	Southern Company				Alabama Power				Georgia Power				Gulf Power				Mississippi Power
	(in millions)
Three Months Ended June 30, 2012
Service cost		$	6			$	2			$	2			$	1			$	1
Interest cost			21				6				10				1				1
Expected return on plan assets			(15	)			(6	)			(7	)			(1	)			(1	)
Net amortization			5				1				2				—				—
Net cost (income)		$	17			$	3			$	7			$	1			$	1
Six Months Ended June 30, 2012
Service cost		$	11			$	3			$	3			$	1			$	1
Interest cost			42				11				19				2				2
Expected return on plan assets			(30	)			(12	)			(14	)			(1	)			(1	)
Net amortization			10				3				5				—				—
Net cost (income)		$	33			$	5			$	13			$	2			$	2
Three Months Ended June 30, 2011
Service cost		$	5			$	2			$	2			$	1			$	1
Interest cost			23				6				10				1				1
Expected return on plan assets			(16	)			(7	)			(7	)			(1	)			(1	)
Net amortization			5				1				2				—				—
Net cost (income)		$	17			$	2			$	7			$	1			$	1
Six Months Ended June 30, 2011
Service cost		$	10			$	3			$	4			$	1			$	1
Interest cost			46				12				20				2				2
Expected return on plan assets			(32	)			(13	)			(15	)			(1	)			(1	)
Net amortization			10				3				5				—				—
Net cost (income)		$	34			$	5			$	14			$	2			$	2