Note 15 - Income Taxes - Income Tax Provision Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016
Tax (benefit) expense on taxable (loss) income at statutory rate of 34.0%	$ (83)	$ 1,123
State and Puerto Rico income taxes, net of Federal income tax benefit	(248)	263
USA 179D and Canadian R&D tax credits	(603)
Permanent differences	458	186
Worthless stock deduction	(2,861)
Foreign income tax rates	(92)	17
Impact on net deferred tax assets from 2018 Federal tax rate change	1,015
Transition repatriation taxes	198
Other	(39)	(45)
Total income tax (benefit) expense	$ (2,255)	$ 1,544