Document And Entity Information - shares	3 Months Ended
	Apr. 01, 2018	May 05, 2018
Document Information [Line Items]
Entity Registrant Name	INTERFACE INC
Entity Central Index Key	0000715787
Trading Symbol	tile
Current Fiscal Year End Date	--12-30
Entity Filer Category	Large Accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	Yes
Entity Common Stock, Shares Outstanding (in shares)		59,494,324
Document Type	10-Q
Document Period End Date	Apr. 01, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q1
Amendment Flag	false