| Document and Entity Information | Apr. 28, 2021 |
| Cover [Abstract] | |
| Entity Registrant Name | CONTANGO OIL & GAS CO |
| Amendment Flag | false |
| Entity Central Index Key | 0001071993 |
| Document Type | 8-K |
| Document Period End Date | Apr. 28, 2021 |
| Entity Incorporation State Country Code | TX |
| Entity File Number | 001-16317 |
| Entity Tax Identification Number | 95-4079863 |
| Entity Address, Address Line One | 111 E. 5th Street |
| Entity Address, Address Line Two | Suite 300 |
| Entity Address, City or Town | Fort Worth |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 76102 |
| City Area Code | (817) |
| Local Phone Number | 529-0059 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, Par Value $0.04 per share |
| Trading Symbol | MCF |
| Security Exchange Name | NYSEAMER |
| Entity Emerging Growth Company | false |
