Note 10 - Income Taxes - Income Tax Benefit Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Tax at statutory tax rate	$ 1,113	$ (2,246)	$ (848)
State income taxes, net of federal tax benefit	(90)	(53)	(153)
Research and development tax credit	(869)	(557)	(814)
Valuation allowance	0	(19)	0
PPP loan forgiveness	0	0	(2,100)
Deferred tax adjustment for stock option forfeitures	0	0	371
Other adjustments to deferred taxes	315	213	230
Other	(71)	38	31
Provision (benefit) for income taxes	$ 398	$ (2,624)	$ (3,283)