Condensed Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Net cash paid for capitalized interest	$ 94	$ 88
Alabama Power [Member]
Net cash paid for capitalized interest	8	15
Georgia Power [Member]
Net cash paid for capitalized interest	15	10
Gulf Power [Member]
Net cash paid for capitalized interest	0	5
Mississippi Power [Member]
Interest paid	72	58
Net cash paid for capitalized interest	36	52
Southern Power [Member]
Net cash paid for capitalized interest	$ 32	$ 4