Summary of significant accounting policies - Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term investments	$ 38,900
Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	76,431	$ 140,856
Short-term investments	38,931	0
Total financial assets	115,362	140,856
Level 1 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	76,431	140,856
Short-term investments	38,931	0
Total financial assets	115,362	140,856
Level 2 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	0	0
Short-term investments	0	0
Total financial assets	0	0
Level 3 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	0	0
Short-term investments	0	0
Total financial assets	$ 0	$ 0