Document And Entity Information (USD $)
12 Months Ended
Jun. 30, 2012
Aug. 29, 2012
Dec. 31, 2011
Document And Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Jun. 30, 2012    
Document Fiscal Year Focus 2012    
Document Fiscal Period Focus FY    
Entity Registrant Name CONTANGO OIL & GAS CO    
Entity Central Index Key 0001071993    
Current Fiscal Year End Date --06-30    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock, Shares Outstanding   15,292,448  
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Public Float     $ 745,499,902