Common stock - Warrants (Details) - Warrants - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Jun. 02, 2023
Class of Warrant or Right [Line Items]
Warrants exercised, numbers	0	0	0	0
Series A Warrants
Class of Warrant or Right [Line Items]
Warrants outstanding					803,112
Exercise price					$ 9.00
Series B Warrants
Class of Warrant or Right [Line Items]
Warrants outstanding	500,000		500,000
Exercise price	$ 10.00		$ 10.00