Accounts Receivable, net (Details - Allowance for Doubtful Accounts) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Receivables [Abstract]
Balance as of January 1	$ 245	$ 462	$ 633
Addition	2,760	187	101
Reversal	(25)	(12)	(225)
Written off	(150)	(396)	(45)
Foreign currency translation difference	(10)	4	(2)
Balance as of December 31	$ 2,820	$ 245	$ 462