Summary of significant accounting policies - Accounts receivable (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Summary of Significant Accounting Policies
Accounts receivable, net	$ 13,779	$ 16,994	$ 9,729
Allowance for doubtful accounts	960	45
Roll-forward of allowance for credit losses
Allowance for credit losses, beginning of period	45	45
Change in provision	915	0
Allowance for credit losses, end of period	$ 960	$ 45