Note 1 - Summary of Significant Accounting Policies - Computation of Basic and Diluted Income (Loss) Per Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Weighted average common shares (in shares)	41,947	41,229	41,764	41,075
Effect of dilutive securities (in shares)	0	0	0	0
Weighted Average Number of Shares Outstanding, Diluted, Total	41,947	41,229	41,764	41,075