Leases - Operating leases in condensed consolidated statements of operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Lessee, Lease, Description [Line Items]
Operating Lease, Expense	$ 30	$ 30	$ 60	$ 60
Research and development [Member]
Lessee, Lease, Description [Line Items]
Operating Lease, Expense	19	19	38	38
General and administrative [Member]
Lessee, Lease, Description [Line Items]
Operating Lease, Expense	$ 11	$ 11	$ 22	$ 22