Cover
| Cover | May 06, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | May 6, 2020 |
| Entity File Number | 001-31446 |
| Entity Registrant Name | CIMAREX ENERGY CO. |
| Entity Central Index Key | 0001168054 |
| Entity Tax Identification Number | 45-0466694 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 1700 Lincoln Street |
| Entity Address, Address Line Two | Suite 3700 |
| Entity Address, City or Town | Denver |
| Entity Address, State or Province | CO |
| Entity Address, Postal Zip Code | 80203 |
| City Area Code | 303 |
| Local Phone Number | 295-3995 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock ($0.01 par value) |
| Trading Symbol | XEC |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |