| Document and Entity Information | Jan. 10, 2020 |
| Cover [Abstract] | |
| Entity Registrant Name | Jagged Peak Energy Inc. |
| Amendment Flag | false |
| Entity Central Index Key | 0001685715 |
| Current Fiscal Year End Date | --12-31 |
| Document Type | 8-K |
| Document Period End Date | Jan. 10, 2020 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-37995 |
| Entity Tax Identification Number | 81-3943703 |
| Entity Address, Address Line One | 303 Colorado Street |
| Entity Address, Address Line Two | Suite 3000 |
| Entity Address, City or Town | Austin |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 78701 |
| City Area Code | (737) |
| Local Phone Number | 704-2300 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common stock, par value $0.01 per share |
| Trading Symbol | JAG |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
