| Document and Entity Information | Aug. 05, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Aug. 5, 2021 |
| Entity Registrant Name | Neoleukin Therapeutics, Inc. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-36327 |
| Entity Tax Identification Number | 98-0542593 |
| Entity Address, Address Line One | 188 East Blaine Street, Suite 450 |
| Entity Address, City or Town | Seattle |
| Entity Address, State or Province | WA |
| Entity Address, Postal Zip Code | 98102 |
| City Area Code | 866 |
| Local Phone Number | 245-0312 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.000001 par value |
| Trading Symbol | NLTX |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Amendment Flag | false |
| Entity Central Index Key | 0001404644 |
