Consolidated Condensed Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jul. 03, 2011	Jul. 04, 2010	Jul. 03, 2011	Jul. 04, 2010
Consolidated Condensed Statements of Operations [Abstract]
NET SALES	$ 267,640	$ 226,587	$ 513,042	$ 443,778
Cost of Sales	172,865	146,453	331,339	290,270
GROSS PROFIT ON SALES	94,775	80,134	181,703	153,508
Selling, General and Administrative Expenses	68,638	58,668	134,038	115,156
Restructuring Charge				3,131
OPERATING INCOME	26,137	21,466	47,665	35,221
Interest Expense	6,783	8,115	13,439	16,937
Bond Retirement Expense				1,085
Other Expense	171	447	49	545
INCOME FROM OPERATIONS BEFORE INCOME TAX EXPENSE	19,183	12,904	34,177	16,654
Income Tax Expense	6,369	4,896	11,539	6,540
NET INCOME	12,814	8,008	22,638	10,114
Income Attributable to Non-Controlling Interest in Subsidiary		(376)		(612)
NET INCOME ATTRIBUTABLE TO INTERFACE, INC.	$ 12,814	$ 7,632	$ 22,638	$ 9,502
Earnings Per Share Attributable to Interface, Inc. Common Shareholders - Basic	$ 0.20	$ 0.12	$ 0.35	$ 0.15
Earnings Per Share Attributable to Interface, Inc. Common Shareholders - Diluted	$ 0.20	$ 0.12	$ 0.35	$ 0.15
Common Shares Outstanding - Basic	65,398	63,515	65,108	63,423
Common Shares Outstanding - Diluted	65,677	64,118	65,363	63,917