| Document and Entity Information Document | Apr. 27, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Apr. 27, 2020 |
| Entity Registrant Name | CNX Midstream Partners LP |
| Entity Central Index Key | 0001610418 |
| Amendment Flag | false |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-36635 |
| Entity Tax Identification Number | 47-1054194 |
| Entity Address, Address Line One | 1000 CONSOL Energy Drive |
| Entity Address, City or Town | Canonsburg |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 15317-6506 |
| City Area Code | 724 |
| Local Phone Number | 485-4000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Units Representing Limited Partner Interests |
| Trading Symbol | CNXM |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
