Note 11 - Commitments and Contingencies (Details Textual) - USD ($)	1 Months Ended	3 Months Ended
	Dec. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Operating Lease, Expense		$ 55,000	$ 51,000
Lessee, Operating Lease, Renewal Term (Year)		4 years
Lessee, Operating Lease, Discount Rate		18.00%
Lessee, Operating Lease, Liability, to be Paid, Total		$ 667,000
Consulting Services, Monthly Payment		$ 23,000
Consulting Services, Period of Services (Year)		4 years
Consulting Services, Three Consecutive Month Average Revenue Threshold for Consulting Fees to Accrue	$ 250,000
Contractual Obligation, Total	$ 1,100,000
Corporate Office Lease [Member]
Lessee Operating, Lease Annual Escalation Rate		3.00%
Lessee, Operating Lease, Renewal Term (Year)		4 years
Oak Ridge, Tennessee Facility Lease [Member]
Lessee, Operating Lease, Renewal Term (Year)		5 years