INCOME TAXES (Details - Unrecognized tax benefit) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefit, Balance at beginning of year	$ 4,320	$ 4,629	$ 3,615
Decrease related to prior year tax positions		(34)
Increases related to prior year tax positions	1,382		896
Increases related to current year tax positions	3	119	111
Expiration of the statute of limitations for the assessment of taxes	(221)	(393)	0
Increase (decrease) related to change in rate	0	(1)	7
Unrecognized tax benefit, Balance at end of year	$ 5,484	$ 4,320	$ 4,629