Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Accrued expenses and other current liabilities
Accrued expenses	$ 12,256	$ 11,696
Cylinder deposits	17,225	13,638
Lease obligations	$ 1,893	$ 1,669
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Total	Total
Other current liabilities	$ 163	$ 905
Total	$ 31,537	$ 27,908