Income taxes (Details - Reconciliation) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount	$ 3,496	$ 392
Federal income tax expense computed at the statutory rate, percentage	21.00%	21.00%
Tax reconciliation not required	21.00%	21.00%
State and local tax expense, net	$ 1,126	$ 287
State and local tax expense, net, percentage	6.80%	15.40%
Other permanent differences	$ 17	$ 8
Other permanent differences, percentage	0.10%	0.40%
Section 162m	$ 435	$ 229
Section 162m, percentage	2.60%	12.20%
Stock based compensation	$ 203	$ 127
Stock based compensation, percentage	1.20%	6.80%
Change in tax rates	$ 5	$ (83)
Change in tax rates, percentage	0.00%	4.40%
Other	$ 0	$ (43)
Other, percentage	0.00%	2.30%
Provision for income taxes	$ 5,282	$ 917
Provision for income taxes, percentage	31.70%	49.10%