Nuclear Insurance (Details) (USD $)	1 Months Ended	12 Months Ended
	Apr. 30, 2014	Dec. 31, 2014
Jointly Owned Utility Plant Interests [Line Items]
Maximum fund for public liability claims arising from a single nuclear incident under Price-Anderson Amendments Act		$ 13,600,000,000
Maximum insurance coverage provided by American Nuclear Insurers to each nuclear plant		375,000,000
Maximum amount that a company could be assessed per incident for each licensed reactor		127,000,000
Maximum aggregate amount that a reactor can assess in a calendar period for each incident		19,000,000
Block period considered for inflation adjustment against maximum assessment per reactor		5 years
Maximum deductible waiting period		26 weeks
Maximum coverage per occurrence per unit limit to obtain replacement power		490,000,000
Approximate period over which maximum per occurrence per unit limit is exhausted		3 years
Aggregate payment for claims resulting from terrorist acts in one year period		3,200,000,000
Vogtle Units 3 and 4 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Maximum limits for accidental property damage occurring during construction		2,750,000,000
Alabama Power [Member]
Jointly Owned Utility Plant Interests [Line Items]
Maximum fund for public liability claims arising from a single nuclear incident under Price-Anderson Amendments Act		13,600,000,000
Maximum insurance coverage provided by American Nuclear Insurers to each nuclear plant		375,000,000
Maximum amount that a company could be assessed per incident for each licensed reactor		127,000,000
Maximum aggregate amount that a reactor can assess in a calendar period for each incident		19,000,000
Maximum assessment, excluding any applicable state premium taxes		255,000,000
Maximum aggregate amount to be paid in one year		38,000,000
Block period considered for inflation adjustment against maximum assessment per reactor		5 years
Block period considered for inflation adjustment against maximum yearly assessment		5 years
Maximum property damage insurance provided to nuclear generating facilities		1,500,000,000
Maximum additional coverage provided for losses under excess insurance	750,000,000	1,250,000,000
Maximum Sublimit Non-Nuclear Losses		750,000,000
Maximum deductible waiting period		26 weeks
Maximum Deductible Waiting Period Days		182 days
Maximum coverage per occurrence per unit limit to obtain replacement power		490,000,000
Approximate period over which maximum per occurrence per unit limit is exhausted		3 years
Elected deductible waiting period		12-week
Current maximum annual assessments under NEIL policies		50,000,000
Aggregate payment for claims resulting from terrorist acts in one year period		3,200,000,000
Elected Deductible Waiting Period, Days		84 days
Georgia Power [Member]
Jointly Owned Utility Plant Interests [Line Items]
Maximum fund for public liability claims arising from a single nuclear incident under Price-Anderson Amendments Act		13,600,000,000
Maximum insurance coverage provided by American Nuclear Insurers to each nuclear plant		375,000,000
Maximum amount that a company could be assessed per incident for each licensed reactor		127,000,000
Maximum aggregate amount that a reactor can assess in a calendar period for each incident		19,000,000
Maximum assessment, excluding any applicable state premium taxes		247,000,000
Maximum aggregate amount to be paid in one year		37,000,000
Block period considered for inflation adjustment against maximum assessment per reactor		5 years
Block period considered for inflation adjustment against maximum yearly assessment		5 years
Maximum property damage insurance provided to nuclear generating facilities		1,500,000,000
Maximum additional coverage provided for losses under excess insurance		1,250,000,000
Maximum Sublimit Non-Nuclear Losses		750,000,000
Maximum deductible waiting period		26 weeks
Maximum coverage per occurrence per unit limit to obtain replacement power		490,000,000
Approximate period over which maximum per occurrence per unit limit is exhausted		3 years
Elected deductible waiting period		12-week
Current maximum annual assessments under NEIL policies		72,000,000
Aggregate payment for claims resulting from terrorist acts in one year period		3,200,000,000
Georgia Power [Member] | Vogtle Units 3 and 4 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Maximum limits for accidental property damage occurring during construction		$ 2,750,000,000