Financing - Schedule of Long-Term Debt Financing Activities (Details) - USD ($)	1 Months Ended	6 Months Ended
	May 31, 2016	Jun. 30, 2016
Debt Instrument [Line Items]
Senior Note Issuances		$ 10,791,000,000
Senior Note Maturities and Redemptions		825,000,000
Revenue Bond Maturities Redemptions and Repurchases		4,000,000
Other Long-Term Debt Issuances		1,247,000,000
Other Long-Term Debt Redemptions and Maturities		443,000,000
Consolidation, Eliminations [Member]
Debt Instrument [Line Items]
Senior Note Issuances		0
Senior Note Maturities and Redemptions		0
Revenue Bond Maturities Redemptions and Repurchases		0
Other Long-Term Debt Issuances		(200,000,000)
Other Long-Term Debt Redemptions and Maturities		(225,000,000)
Southern Company [Member]
Debt Instrument [Line Items]
Senior Note Issuances	$ 8,500,000,000.0	8,500,000,000
Senior Note Maturities and Redemptions		0
Revenue Bond Maturities Redemptions and Repurchases		0
Other Long-Term Debt Issuances		0
Other Long-Term Debt Redemptions and Maturities		0
Alabama Power [Member]
Debt Instrument [Line Items]
Senior Note Issuances		400,000,000
Senior Note Maturities and Redemptions		200,000,000
Revenue Bond Maturities Redemptions and Repurchases		0
Other Long-Term Debt Issuances		45,000,000
Other Long-Term Debt Redemptions and Maturities		0
Georgia Power [Member]
Debt Instrument [Line Items]
Senior Note Issuances		650,000,000
Senior Note Maturities and Redemptions		500,000,000
Revenue Bond Maturities Redemptions and Repurchases		4,000,000
Other Long-Term Debt Issuances		300,000,000
Other Long-Term Debt Redemptions and Maturities		3,000,000
Gulf Power [Member]
Debt Instrument [Line Items]
Senior Note Issuances		0
Senior Note Maturities and Redemptions		125,000,000
Revenue Bond Maturities Redemptions and Repurchases		0
Other Long-Term Debt Issuances		0
Other Long-Term Debt Redemptions and Maturities		0
Mississippi Power [Member]
Debt Instrument [Line Items]
Senior Note Issuances		0
Senior Note Maturities and Redemptions		0
Revenue Bond Maturities Redemptions and Repurchases		0
Other Long-Term Debt Issuances		1,100,000,000
Other Long-Term Debt Redemptions and Maturities		651,000,000
Southern Power [Member]
Debt Instrument [Line Items]
Senior Note Issuances		1,241,000,000
Senior Note Maturities and Redemptions		0
Revenue Bond Maturities Redemptions and Repurchases		0
Other Long-Term Debt Issuances		2,000,000
Other Long-Term Debt Redemptions and Maturities		4,000,000
Other [Member]
Debt Instrument [Line Items]
Senior Note Issuances		0
Senior Note Maturities and Redemptions		0
Revenue Bond Maturities Redemptions and Repurchases		0
Other Long-Term Debt Issuances		0
Other Long-Term Debt Redemptions and Maturities		$ 10,000,000