Note 5 - Financial Instruments Measured at Fair Value - Short-term Investments by Security Type (Details) - USD ($) $ in Thousands		Jun. 27, 2020	Dec. 28, 2019
Estimated Fair Value		$ 920	$ 904	[1]
Debt Security, Government, Non-US [Member]
Amortized Cost		920	904
Gross Unrealized Gains		0	0
Gross Unrealized Losses	[2]	0	0
Estimated Fair Value		$ 920	$ 904

[1] Derived from December 28, 2019 audited financial statements

[2] As of June 27, 2020 and December 28, 2019, there were no investments in our portfolio in a loss position.