Derivatives - Pre-tax Effects of Derivatives Designated as Cash Flow Hedging Instruments (Details) (Energy Related Derivative [Member], USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Southern Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	$ 4	$ (32)
Alabama Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	9	(1)
Georgia Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(8)	(16)
Gulf Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	1	(10)
Mississippi Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	2	(5)
Other regulatory assets current [Member] | Southern Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(19)	(26)
Other regulatory assets current [Member] | Alabama Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(2)	(3)
Other regulatory assets current [Member] | Georgia Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(11)	(13)
Other regulatory assets current [Member] | Gulf Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(4)	(6)
Other regulatory assets current [Member] | Mississippi Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(2)	(4)
Other regulatory assets deferred [Member] | Southern Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(17)	(29)
Other regulatory assets deferred [Member] | Alabama Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(3)	(5)
Other regulatory assets deferred [Member] | Georgia Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(4)	(8)
Other regulatory assets deferred [Member] | Gulf Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(7)	(11)
Other regulatory assets deferred [Member] | Mississippi Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(3)	(6)
Other regulatory liabilities current [Member] | Southern Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	31	16
Other regulatory liabilities current [Member] | Alabama Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	12	5
Other regulatory liabilities current [Member] | Georgia Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	6	3
Other regulatory liabilities current [Member] | Gulf Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	8	5
Other regulatory liabilities current [Member] | Mississippi Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	5	3
Other regulatory liabilities deferred [Member] | Southern Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	9	7
Other regulatory liabilities deferred [Member] | Alabama Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	2	2
Other regulatory liabilities deferred [Member] | Georgia Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	1	2
Other regulatory liabilities deferred [Member] | Gulf Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	4	2
Other regulatory liabilities deferred [Member] | Mississippi Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	$ 2	$ 2