| Cover | Feb. 22, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Feb. 22, 2022 |
| Entity File Number | 001-39918 |
| Entity Registrant Name | Perpetua Resources Corp. |
| Entity Central Index Key | 0001526243 |
| Entity Tax Identification Number | 26-4675940 |
| Entity Incorporation, State or Country Code | A1 |
| Entity Address, Address Line One | 405 S. 8th Street |
| Entity Address, Address Line Two | Ste. 201 |
| Entity Address, City or Town | Boise |
| Entity Address, State or Province | ID |
| Entity Address, Postal Zip Code | 83702 |
| City Area Code | 208 |
| Local Phone Number | 901-3060 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Shares, without par value |
| Trading Symbol | PPTA |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
