Note 1 - Summary of Significant Accounting Policies (Details Textual) - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
	Aug. 07, 2018	Dec. 30, 2018	Dec. 31, 2017	Jan. 01, 2017
Percent of Revenue Due to Contracts With Customers		100.00%
Percent of Warranty Claims to Revenue		0.30%
Research and Development Expense, Total		$ 16,400	$ 14,000	$ 14,300
Cash Equivalents, at Carrying Value, Total		0	0
Short-term Investments, Total		0	0
Interest Paid, Excluding Capitalized Interest, Operating Activities		13,800	6,300	5,500
Income Taxes Paid		29,500	19,100	12,800
Proceeds from Income Tax Refunds		800	100	200
Interest Costs Capitalized		700	600	500
Depreciation, Total		37,600	29,500	30,100
Finite-Lived Intangible Assets, Accumulated Amortization		77,300	77,300
Goodwill, Impaired, Accumulated Impairment Loss		212,600	212,600
Goodwill, Ending Balance		245,815	68,754
Goodwill, Purchase Accounting Adjustments		$ 1,377
Number of Operating Segments		3
Other Intangible Assets, Net		$ 97,700	600
Amortization of Intangible Assets, Total		5,387	0	0
Goodwill, Impairment Loss		$ 0	0	0
Fair Value Estimates of Reporting Units, Threshold for No Goodwill Impairment, Percent of Decrease in Fair Value Estimates		10.00%
Workmanship Warranty Period		1 year
Standard Product Warranty Accrual, Ending Balance		$ 3,500	4,100
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent, Total		$ (22,544)	$ 31,579	$ (19,011)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross		0	0	0
Accrual for Environmental Loss Contingencies, Ending Balance		$ 0	$ 0
Restructuring Charges [Member]
Impairment of Intangible Assets (Excluding Goodwill), Total				$ 3,400
Nora [Member]
Goodwill, Ending Balance	$ 184,725	184,700
Finite-Lived Intangible Assets, Net, Ending Balance	103,300	97,700
Goodwill, Purchase Accounting Adjustments	1,400	1,400
Business Acquisition, Goodwill, Expected Tax Deductible Amount	$ 0	0
Amortization of Intangible Assets, Total		$ 5,400	$ 700	$ 500
Building and Building Improvements [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life		10 years
Building and Building Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life		40 years
Furniture and Fixtures [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life		3 years
Furniture and Fixtures [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life		12 years
Carpet, Modular Resilient Flooring, and Related Products [Member]
Percent of Revenue Due to Contracts With Customers		97.00%
Carpet Products [Member] | Minimum [Member]
Product Warranty Period		10 years
Carpet Products [Member] | Maximum [Member]
Product Warranty Period		20 years
Luxury Vinyl Tile Products [Member] | Minimum [Member]
Product Warranty Period		5 years
Luxury Vinyl Tile Products [Member] | Maximum [Member]
Product Warranty Period		15 years