Stock-based compensation - Compensation expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Stock-based compensation
Stock-based compensation	$ 14,785	$ 11,153	$ 9,344
Employee Stock Option
Stock-based compensation
Stock-based compensation	9,727	7,627	5,938
Restricted stock awards and units
Stock-based compensation
Stock-based compensation	4,734	3,241	3,215
Employee stock purchase plan awards
Stock-based compensation
Stock-based compensation	323	285	191
General and administrative
Stock-based compensation
Stock-based compensation	8,746	7,568	6,398
Research and development
Stock-based compensation
Stock-based compensation	$ 6,039	$ 3,585	$ 2,946