Note 5 - Leases (Details Textual) - USD ($) $ in Thousands	Nov. 09, 2020	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Lease, Right-of-Use Asset		$ 1,522	$ 1,598	$ 1,773
Operating Lease, Liability, Total		$ 1,644		$ 1,896
Minimum [Member]
Lessee, Operating Lease, Remaining Lease Term (Year)		4 years
Maximum [Member]
Lessee, Operating Lease, Remaining Lease Term (Year)		6 years
Corporate Office Facility in Seattle, Washington [Member]
Lessee, Operating Lease, Term of Contract (Month)						87 months
Office Facility in the UK [Member]
Lessee, Operating Lease, Renewal Term (Month)	120 months
Lessee Operating Lease, Termination Option Term (Year)	5 years
Operating Lease, Right-of-Use Asset					$ 400
Operating Lease, Liability, Total					$ 400