Note 9 - Income Taxes - Reconciliation of Income Tax Computed at U.S. Federal Statutory Tax Rate to Provision (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 26, 2020	Dec. 28, 2019	Dec. 29, 2018
Tax provision at U.S. 21% statutory rate	$ (2,757)	$ (15,136)	$ (6,702)
Impact of Tax Act, before reduction in valuation allowance	0	0	5,095
State income taxes, net of federal tax benefit	(1,160)	(1,097)	(663)
Settlements, adjustments and releases from statute expirations	(118)	(1,204)	(783)
Federal tax credits	(46)	(1,458)	(864)
Stock-based compensation	727	587	(838)
Executive compensation limited by Section 162(m)	491	190	3,456
Change in valuation allowance	(1,691)	11,270	(2,015)
Non-deductible transaction related costs	0	0	1,106
Deemed dividend	1,224	1,453	470
GILTI	4,191	2,480	3,531
Foreign rate differential	(1,512)	(1,266)	(904)
Other, net	1,317	1,099	(258)
Income Tax Expense (Benefit), Total	$ 666	$ (3,082)	$ 631