Employee benefit plan (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) hour	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Retirement Benefits [Abstract]
Eligible age to participate	21 years
Minimum number of hours for eligibility | hour	1,000
Maximum contribution by employee (as a percent)	95.00%
Percentage employer matches of the employee's percentage contribution matched	100.00%	100.00%	100.00%
Employer matching contribution (as a percent)	4.00%	4.00%	4.00%
Employee benefit expenses | $	$ 1.3	$ 1.1	$ 0.8