Prepaid expenses and other current assets - Schedule of Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid insurance	$ 3,347	$ 4,265
Prepaid expenses	2,386	2,217
Pre-contract costs	868	546
Total prepaid expenses and other current assets	$ 6,601	$ 7,028