Note 7 - Income Taxes - Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Allowance for uncollectable accounts	$ 85	$ 79
Inventories reserve	531	348
Accrued vacation	115	112
Accrued bonus	57	171
Stock-based compensation and equity appreciation rights	78	62
Lease Accounting ASC 842 Lease Liability	1,405	1,230
Section 481(a) adjustment	798	716
Net operating loss carryforwards	82	97
Tax credit carryforwards	165	171
Unrealized Foreign Currency Gain	42
Other	5	7
Total	3,363	2,993
Valuation allowance	(1,504)	(1,403)
Deferred tax assets	1,859	1,590
Accumulated Other Comprehensive Income	(61)
Lease Accounting ASC 842 Lease Asset	(1,386)	(1,158)
Property and equipment	(412)	(432)
Deferred tax liabilities	(1,859)	(1,590)
Net deferred tax assets