Note 5 - Leases (Details Textual) $ in Thousands	1 Months Ended	3 Months Ended	6 Months Ended
	Aug. 31, 2020 USD ($) ft²	Jun. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2017 ft²
Short-term and Variable Lease, Cost			$ 200
Lease, Cost, Total			900	$ 800
Operating Lease, Payments			$ 1,500	$ 1,000
Operating Lease, Weighted Average Remaining Lease Term (Year)		2 years 4 months 24 days	2 years 4 months 24 days
Operating Lease, Weighted Average Discount Rate, Percent		7.63%	7.63%
Sublease Income		$ 700	$ 1,400
Proceeds from Lease Payment, Operating Activity		$ 700	$ 1,400
The 1020 Marsh Road Facility [Member]
Area of Real Estate Property (Square Foot) | ft²					34,500
Lessee, Operating Lease, Term of Contract (Month)					87 months
Lessee, Operating Lease, Number of Renewal Options					1
Lessee, Operating Lease, Renewal Term (Year)					5 years
Office Space in North Carolina [Member]
Area of Real Estate Property (Square Foot) | ft²	4,128
Lessee, Operating Lease, Term of Contract (Month)	63 months
Lessee, Operating Lease, Monthly Payments	$ 9
Lessee, Operating Lease, Abatement Term (Month)	3 months