Income Taxes, Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred Tax Assets [Abstract]
Federal and state operating loss carryforwards	$ 12,780	$ 13,087
Acquired intangibles	547	547
Deferral of research and development costs	3,794	2,820
Organizational costs	6	7
Other	72	62
Stock-based compensation	1,835	1,152
Research and development credit carryforward	1,107	731
Subtotal	20,141	18,406
Valuation allowance	(20,141)	(17,770)
Total deferred tax assets, net of valuation allowance	0	636
Deferred Tax Liabilities [Abstract]
Deferred revenue	0	(636)
Total deferred tax liabilities	0	(636)
Net deferred tax assets	$ 0	$ 0