Retirement Benefits (Tables)

3 Months Ended

Mar. 31, 2013

Compensation and Retirement Disclosure [Abstract]

Pension Plans and Postretirement Plans

Components of the net periodic benefit costs for the three months ended March 31, 2013 and 2012 were as follows:

Pension Plans	Southern Company			Alabama Power			Georgia Power			Gulf Power			Mississippi   Power
	(in millions)
Three Months Ended March 31, 2013
Service cost	$	58		$	13		$	17		$	3		$	3
Interest cost	97			23			34			4			5
Expected return on plan assets	(151		)	(39		)	(53		)	(6		)	(7		)
Amortization:
Prior service costs	7			2			3			—			—
Net (gain)/loss	50			13			19			2			2
Net cost	$	61		$	12		$	20		$	3		$	3
Three Months Ended March 31, 2012
Service cost	$	50		$	11		$	15		$	2		$	2
Interest cost	98			23			35			4			5
Expected return on plan assets	(145		)	(40		)	(55		)	(6		)	(6		)
Amortization:
Prior service costs	7			2			3			—			—
Net (gain)/loss	24			6			8			1			1
Net cost	$	34		$	2		$	6		$	1		$	2

Postretirement Benefits	Southern Company			Alabama Power			Georgia Power			Gulf Power		Mississippi Power
	(in millions)
Three Months Ended March 31, 2013
Service cost	$	6		$	2		$	2		$	—	$	—
Interest cost	19			5			8			1		1
Expected return on plan assets	(14		)	(6		)	(6		)	—		—
Amortization:
Transition obligation	1			—			1			—		—
Prior service costs	1			1			—			—		—
Net (gain)/loss	3			—			2			—		—
Net cost	$	16		$	2		$	7		$	1	$	1
Three Months Ended March 31, 2012
Service cost	$	5		$	1		$	1		$	—	$	—
Interest cost	21			5			9			1		1
Expected return on plan assets	(15		)	(6		)	(7		)	—		—
Amortization:
Transition obligation	2			1			2			—		—
Prior service costs	1			1			—			—		—
Net (gain)/loss	2			—			1			—		—
Net cost	$	16		$	2		$	6		$	1	$	1