v2.4.0.8
Document and Entity Information
9 Months Ended
Sep. 30, 2013
Nov. 01, 2013
Entity Information    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2013  
Document Fiscal Year Focus 2013  
Document Fiscal Period Focus Q3  
Entity Registrant Name ENERGEN CORP  
Entity Central Index Key 0000277595  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Entity Common Stock, Shares Outstanding   72,685,415
Alabama Gas Corporation
   
Entity Information    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2013  
Document Fiscal Year Focus 2013  
Document Fiscal Period Focus Q3  
Entity Registrant Name ALABAMA GAS CORP  
Entity Central Index Key 0000003146  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Entity Common Stock, Shares Outstanding   1,972,052