| Document and Entity Information | Nov. 04, 2020 |
| Cover [Abstract] | |
| Entity Registrant Name | Altus Midstream Co |
| Amendment Flag | false |
| Entity Central Index Key | 0001692787 |
| Document Type | 8-K |
| Document Period End Date | Nov. 4, 2020 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-38048 |
| Entity Tax Identification Number | 81-4675947 |
| Entity Address, Address Line One | One Post Oak Central |
| Entity Address, Address Line Two | 2000 Post Oak Boulevard |
| Entity Address, Address Line Three | Suite 100 |
| Entity Address, City or Town | Houston |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 77056-4400 |
| City Area Code | (713) |
| Local Phone Number | 296-6000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Class A common stock, $0.0001 par value |
| Trading Symbol | ALTM |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
