Document And Entity Information - USD ($)	12 Months Ended
	Jan. 01, 2017	Feb. 17, 2017	Jul. 01, 2016
Document Information [Line Items]
Entity Registrant Name	INTERFACE INC
Entity Central Index Key	0000715787
Trading Symbol	tile
Current Fiscal Year End Date	--01-01
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)		64,230,649
Entity Public Float			$ 1,199,061,440
Document Type	10-K
Document Period End Date	Jan. 01, 2017
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	FY
Amendment Flag	false