8. Income Taxes (Details - Deferred Tax Assets and Liabilities) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 19,965	$ 18,771
Net operating loss carryforwards of foreign subsidiaries	374	374
Depreciation expense	(99)	(77)
Stock-based compensation expense	53	36
Other	304	68
Net deferred tax assets	20,597	19,172
Valuation allowance for net deferred tax assets	(20,597)	(19,172)
Net deferred tax assets, net of allowance	$ 0	$ 0