Nature of the business and basis of presentation - Liquidity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Nature of the business and basis of presentation
Cash and cash equivalents	$ 526,423	$ 339,154	$ 438,680
Net loss	180,664	112,717	$ 66,819
Accumulated deficit	$ (511,760)	$ (331,096)