Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Accrued expenses and other current liabilities
Accrued expenses	$ 11,703	$ 12,256
Cylinder deposits	17,807	17,225
Lease obligations	1,778	1,893
Other current liabilities	140	163
Total	$ 31,428	$ 31,537