Income Taxes (Details - Deferred Tax Assets and Liabilities) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 22,497	$ 19,965
Net operating loss carryforwards of foreign subsidiaries	56	374
Depreciation expense	(94)	(99)
Stock-based compensation expense	52	53
Other	544	304
Net deferred tax assets	23,055	20,597
Valuation allowance for net deferred tax assets	(23,055)	(20,597)
Net deferred tax assets, net of allowance	$ 0	$ 0