Condensed Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Southern Company [Member]
Net cash paid for capitalized interest	$ 88	$ 80
Alabama Power [Member]
Net cash paid for capitalized interest	15	13
Georgia Power [Member]
Net cash paid for capitalized interest	10	13
Gulf Power [Member]
Net cash paid for capitalized interest	5	4
Mississippi Power [Member]
Interest paid	58	55
Net cash paid for capitalized interest	52	50
Southern Power [Member]
Net cash paid for capitalized interest	$ 4	$ 0