Note 3 - Summary of Significant Accounting Policies - Remaining Performance Obligations (Details)	Mar. 31, 2021 USD ($)
Revenue, Remaining Performance Obligation, Amount	$ 4,225,000
Service [Member]
Revenue, Remaining Performance Obligation, Amount	2,466,000
Clinical Revenue [Member]
Revenue, Remaining Performance Obligation, Amount	211,000
Exclusivity Fee [Member]
Revenue, Remaining Performance Obligation, Amount	$ 1,548,000