Note 9 - Income Taxes: Schedule of Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Text Block [Abstract]
Property and equipment, principally due to differences in depreciation	$ 85	$ 68
Inventory reserves and other inventory-related temporary basis differences	437	437
Warranty, vacation, deferred rent and other liabilities	(446)	251
Retirement liabilities	504	543
Net operating loss carryforwards	35,205	35,532
Credit carryforwards	0	28
Other	956	181
Total deferred income tax assets	36,741	37,040
Less valuation allowance	(36,741)	(37,040)
Net deferred income tax assets	$ 0	$ 0