Summary of Significant Accounting Policies - Accrual for loss contracts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accrual for loss contracts
Beginning balance	$ 24,013	$ 3,702	$ 5,345
Provision (benefit) for loss accrual	71,988	35,473	(394)
Loss accrual from acquisition	2,636
Released to service cost of sales	(8,864)	(2,348)	(1,249)
Released to provision for warrants		(12,814)
Ending balance	$ 89,773	$ 24,013	$ 3,702