Income Taxes - Components of Net Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets
Accrued bonus	$ 238	$ 222
Deferred tax assets, accrued vacation	50	47
Stock-based compensation	4,203	4,067
Capitalized R&D expenses	5,788	3,155
Rebate reserve	303	0
Intangible assets, net	248	315
Investment in equity securities	628	0
Net operating loss carryforwards	13,276	11,522
Other	6	0
Total gross deferred tax asset	24,740	19,328
Valuation allowance	(24,646)	(19,327)
Net deferred tax assets	94	1
Deferred tax liabilities
Section 481(a) adjustment - bonus compensation	(94)	0
Fixed assets	0	(1)
Net deferred tax asset	$ 0	$ 0