| Document And Entity Information | Jan. 03, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jan. 3, 2021 |
| Entity Registrant Name | SMTC CORPORATION |
| Entity Central Index Key | 0001108320 |
| Current Fiscal Year End Date | --12-27 |
| Entity Emerging Growth Company | false |
| Entity File Number | 000-31051 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 98-0197680 |
| Entity Address, Address Line One | 7050 Woodbine Avenue |
| Entity Address, City or Town | Markham |
| Entity Address, State or Province | ON |
| Entity Address, Country | CA |
| Entity Address, Postal Zip Code | L3R 4G8 |
| City Area Code | 905 |
| Local Phone Number | 479-1810 |
| Written Communications | false |
| Soliciting Material | true |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.01 per share |
| Trading Symbol | SMTX |
| Security Exchange Name | NASDAQ |
