Summary of significant accounting policies, Accounts receivable and credit losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Allowances for expected credit losses [Roll Forward]
Balance, beginning of period	$ 351	$ 219
Additions charged to costs and expenses	606	140
Deductions	(189)	(8)
Balance, end of period	$ 768	$ 351