Document And Entity Information - USD ($)	12 Months Ended
	Jan. 03, 2016	Feb. 19, 2016	Jul. 02, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	INTERFACE INC
Trading Symbol	tile
Document Type	10-K
Current Fiscal Year End Date	--01-03
Entity Common Stock, Shares Outstanding		65,884,825
Entity Public Float			$ 1,585,000,222
Amendment Flag	false
Entity Central Index Key	0000715787
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Document Period End Date	Jan. 03, 2016
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	FY