Document and Entity Information (USD $)	9 Months Ended
	Sep. 30, 2014	Nov. 25, 2014	Mar. 31, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	ALABAMA GAS CORP
Entity Central Index Key	0000003146
Current Fiscal Year End Date	--09-30
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Public Float			$ 0
Entity Common Stock, Shares Outstanding		1,972,052
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Document Type	10-KT
Amendment Flag	false
Document Period End Date	Sep. 30, 2014