Note 6 - Leases (Details Textual) $ in Thousands		1 Months Ended	12 Months Ended		24 Months Ended
	Oct. 01, 2018 USD ($)	Aug. 31, 2020 USD ($) ft²	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2021 USD ($)	Oct. 30, 2018 ft²	Mar. 31, 2017 ft²
Short-term and Variable Lease, Cost			$ 400		$ 500
Lease, Cost, Total			1,600	$ 2,100
Operating Lease, Payments			$ 2,500	$ 2,300
Operating Lease, Weighted Average Remaining Lease Term (Year)			2 years 10 months 24 days	3 years 10 months 24 days	2 years 10 months 24 days
Operating Lease, Weighted Average Discount Rate, Percent			7.60%	7.62%	7.60%
Write-off of Lease Receivable and Prepaid Commission Assets				$ 1,383
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
The 1020 Marsh Road Facility [Member] | EVA Automation, Inc. [Member]
Proceeds from Lease Payment, Operating Activity				1,200
Lessor, Operating Lease, Term of Contract (Month)	72 months
Incentive to Lessee	$ 900
Lessor, Operating Lease, Abatement Term (Month)	5 months
Write-off of Lease Receivable and Prepaid Commission Assets			1,400
Operating Lease, Lease Income (Loss)				$ (13)
Sublease Agreement in Palo Alto, California [Member]
Area of Real Estate Property (Square Foot) | ft²						4,240
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
The 1020 Marsh Facility [Member]
Sublease Income			1,000
Proceeds from Lease Payment, Operating Activity			$ 900