Income taxes (Details - Unrecognized tax benefits) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Unrecognized tax benefits, beginning balance	$ 396	$ 95
Additions based on tax positions of prior years	0	301
Reduction for tax positions of prior years	(396)	0
Reduction for tax positions of prior years	396	0
Unrecognized tax benefits, ending balance	$ 0	$ 396