Condensed Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Southern Company [Member]
Net cash paid for capitalized interest	$ 32	$ 22
Alabama Power [Member]
Net cash paid for capitalized interest	5	4
Georgia Power [Member]
Net cash paid for capitalized interest	6	3
Gulf Power [Member]
Net cash paid for capitalized interest	2	1
Mississippi Power [Member]
Interest paid	17	17
Net cash paid for capitalized interest	18	14
Southern Power [Member]
Net cash paid for capitalized interest	$ 0	$ 0