Summary of Significant Accounting Policies - Fair value hierarchy (Details) - Recurring - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Level 1
Assets:
Cash equivalents - money markets accounts	$ 7,002	$ 7,794
Marketable securities - U.S. Treasuries	$ 76,190	27,802
Level 3
Liability:
Derivative liability - redemption feature on convertible promissory note		$ 5,739