Note 7 - Income Taxes (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2018	Apr. 01, 2017
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ (82,000)
Deferred Tax Assets, Valuation Allowance, Total	9,600,000
Operating Loss Carryforwards, Total	31,200,000
Income Taxes Paid, Net, Total	0	$ 0
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions	$ 19,000
Effective Income Tax Rate Reconciliation, Percent, Total	0.00%	0.00%