Note 2 - Summary of Significant Accounting Policies - Remaining Performance Obligations (Details)	Dec. 31, 2019 USD ($)
Revenue, Remaining Performance Obligation, Amount	$ 3,969,000
Service [Member]
Revenue, Remaining Performance Obligation, Amount	1,828,000
Clinical Revenue [Member]
Revenue, Remaining Performance Obligation, Amount	237,000
Exclusivity Fee [Member]
Revenue, Remaining Performance Obligation, Amount	$ 1,904,000