10. Income taxes (Details - Deferred tax assets) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax liabilities attributable to:
Accumulated depreciation and amortization	$ (2,101)	$ (2,015)
Unrealized gains	(467)	(465)
Total deferred tax liabilities	(2,568)	(2,480)
Deferred tax assets attributable to:
Net operating losses	6	507
Accrued compensation	149	89
Incentive compensation	168	473
Inventory	323	312
Allowances for doubtful accounts and discounts	109	115
Deferred revenue	15	40
Other	34	22
Total net deferred tax assets	804	1,558
Net deferred tax liabilities	$ (1,764)	$ (922)