Leases - Weighted average discount rate and lease term (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Leases
Remaining lease term (in years)	1 year 1 month 28 days	1 year 6 months 10 days	1 year 1 month 28 days	1 year 6 months 10 days
Discount rate	9.25%	10.36%	9.25%	10.36%
Cash paid included in the computation of the operating lease assets and lease liability	$ 30,000	$ 30,000	$ 61,000	$ 61,000