| Document and Entity Information | Nov. 05, 2020 |
| Cover [Abstract] | |
| Entity Address, State or Province | PA |
| Amendment Flag | false |
| Entity Central Index Key | 0001710366 |
| Document Type | 8-K |
| Document Period End Date | Nov. 5, 2020 |
| Entity Registrant Name | CONSOL Energy Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-38147 |
| Entity Tax Identification Number | 82-1954058 |
| Entity Address, Address Line One | 1000 CONSOL Energy Drive |
| Entity Address, Address Line Two | Suite 100 |
| Entity Address, City or Town | Canonsburg |
| Entity Address, Postal Zip Code | 15317 |
| City Area Code | (724) |
| Local Phone Number | 416-8300 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock ($0.01 par value) |
| Trading Symbol | CEIX |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
