| Document and Entity Information | Nov. 09, 2022 |
| Cover [Abstract] | |
| Security Exchange Name | NASDAQ |
| Amendment Flag | false |
| Entity Central Index Key | 0001826600 |
| Document Type | 8-K |
| Document Period End Date | Nov. 09, 2022 |
| Entity Registrant Name | Montauk Renewables, Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 1-39919 |
| Entity Tax Identification Number | 85-3189583 |
| Entity Address, Address Line One | 680 Andersen Drive |
| Entity Address, Address Line Two | 5th Floor |
| Entity Address, City or Town | Pittsburgh |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 15220 |
| City Area Code | (412) |
| Local Phone Number | 747-8700 |
| 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 per share |
| Trading Symbol | MNTK |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
