Common Stock and Stock Compensation - Stock Options, Assumptions Used (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Assumptions used in the pricing model and the weighted average grant-date fair value of stock options granted
Expected volatility	16.60%	17.70%	17.50%
Expected term (in years)	5 years	5 years	5 years
Interest rate	0.90%	0.90%	2.30%
Dividend yield, percentage	4.40%	4.20%	4.80%
Weighted average grant-date fair value	$ 2.93	$ 3.39	$ 3.23
Performance Share Plan [Member]
Assumptions used in the pricing model and the weighted average grant-date fair value of stock options granted
Expected volatility	12.00%	16.00%	19.20%
Expected term (in years)	3 years	3 years	3 years
Interest rate	0.40%	0.40%	1.40%
Dividend yield	$ 1.96	$ 1.89	$ 1.82
Weighted average grant-date fair value	40.50	41.99	35.97
Alabama Power [Member]
Assumptions used in the pricing model and the weighted average grant-date fair value of stock options granted
Expected volatility	16.60%	17.70%	17.50%
Expected term (in years)	5 years	5 years	5 years
Interest rate	0.90%	0.90%	2.30%
Dividend yield, percentage	4.40%	4.20%	4.80%
Weighted average grant-date fair value	2.93	3.39	3.23
Alabama Power [Member] | Performance Share Plan [Member]
Assumptions used in the pricing model and the weighted average grant-date fair value of stock options granted
Expected volatility	12.00%	16.00%	19.20%
Expected term (in years)	3 years	3 years	3 years
Interest rate	0.40%	0.40%	1.40%
Dividend yield	$ 1.96	$ 1.89	$ 1.82
Weighted average grant-date fair value	40.50	41.99	35.97
Georgia Power [Member]
Assumptions used in the pricing model and the weighted average grant-date fair value of stock options granted
Expected volatility	16.60%	17.70%	17.50%
Expected term (in years)	5 years	5 years	5 years
Interest rate	0.90%	0.90%	2.30%
Dividend yield, percentage	4.40%	4.20%	4.80%
Weighted average grant-date fair value	2.93	3.39	3.23
Georgia Power [Member] | Performance Share Plan [Member]
Assumptions used in the pricing model and the weighted average grant-date fair value of stock options granted
Expected volatility	12.00%	16.00%	19.20%
Expected term (in years)	3 years	3 years	3 years
Interest rate	0.40%	0.40%	1.40%
Dividend yield	$ 1.96	$ 1.89	$ 1.82
Weighted average grant-date fair value	40.50	41.99	35.97
Gulf Power [Member]
Assumptions used in the pricing model and the weighted average grant-date fair value of stock options granted
Expected volatility	16.60%	17.70%	17.50%
Expected term (in years)	5 years	5 years	5 years
Interest rate	0.90%	0.90%	2.30%
Dividend yield, percentage	4.40%	4.20%	4.80%
Weighted average grant-date fair value	2.93	3.39	3.23
Gulf Power [Member] | Performance Share Plan [Member]
Assumptions used in the pricing model and the weighted average grant-date fair value of stock options granted
Expected volatility	12.00%	16.00%	19.20%
Expected term (in years)	3 years	3 years	3 years
Interest rate	0.40%	0.40%	1.40%
Dividend yield	$ 1.96	$ 1.89	$ 1.82
Weighted average grant-date fair value	40.50	41.99	35.97
Mississippi Power [Member] | Performance Share Plan [Member]
Assumptions used in the pricing model and the weighted average grant-date fair value of stock options granted
Expected volatility	12.00%	16.00%	19.20%
Expected term (in years)	3 years	3 years	3 years
Interest rate	0.40%	0.40%	1.40%
Dividend yield	$ 1.96	$ 1.89	$ 1.82
Weighted average grant-date fair value	40.50	41.99	35.97
Mississippi Power [Member] | Stock Options [Member]
Assumptions used in the pricing model and the weighted average grant-date fair value of stock options granted
Expected volatility	16.60%	17.70%	17.50%
Expected term (in years)	5 years	5 years	5 years
Interest rate	0.90%	0.90%	2.30%
Dividend yield, percentage	4.40%	4.20%	4.80%
Weighted average grant-date fair value	$ 2.93	$ 3.39	$ 3.23