| Document And Entity Information | Aug. 03, 2021 |
| Document Information [Line Items] | |
| Entity, Registrant Name | Lattice Semiconductor Corporation |
| Document, Type | 8-K |
| Document, Period End Date | Aug. 3, 2021 |
| Entity, Incorporation, State or Country Code | DE |
| Entity, File Number | 000-18032 |
| Entity, Tax Identification Number | 93-0835214 |
| Entity, Address, Address Line One | 5555 NE Moore Court |
| Entity, Address, City or Town | Hillsboro |
| Entity, Address, State or Province | OR |
| Entity, Address, Postal Zip Code | 97124 |
| City Area Code | 503 |
| Local Phone Number | 268-8000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | LSCC |
| Security Exchange Name | NASDAQ |
| Entity, Emerging Growth Company | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0000855658 |
