| Document and Entity Information | Dec. 10, 2020 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001403752 |
| Document Type | 8-K |
| Document Period End Date | Dec. 10, 2020 |
| Entity Registrant Name | Zymeworks Inc. |
| Entity Incorporation State Country Code | A1 |
| Entity File Number | 001-38068 |
| Entity Tax Identification Number | 98-1398788 |
| Entity Address, Address Line One | Suite 540 |
| Entity Address, Address Line Two | 1385 West 8th Avenue |
| Entity Address, City or Town | Vancouver |
| Entity Address, State or Province | BC |
| Entity Address, Country | CA |
| Entity Address, Postal Zip Code | V6H 3V9 |
| City Area Code | (604) |
| Local Phone Number | 678-1388 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Shares, no par value per share |
| Trading Symbol | ZYME |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
