| Document and Entity Information Document | Aug. 07, 2020 |
| Cover page. | |
| Title of 12(b) Security | Common Stock, $0.10 Par Value Per Share |
| Document Type | 8-K |
| Document Period End Date | Aug. 7, 2020 |
| Entity Registrant Name | INTERFACE INC |
| Entity Incorporation, State or Country Code | GA |
| Entity File Number | 001-33994 |
| Entity Tax Identification Number | 58-1451243 |
| Entity Address, Address Line One | 1280 West Peachtree Street NW |
| Entity Address, City or Town | Atlanta |
| Entity Address, State or Province | GA |
| Entity Address, Postal Zip Code | 30309 |
| City Area Code | 770 |
| Local Phone Number | 437-6800 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000715787 |
| Amendment Flag | false |
| Trading Symbol | TILE |
| Security Exchange Name | NASDAQ |
