Note 15 - Equity Transaction - Shares Reserved for Future Issuance (Details) - shares	Mar. 31, 2020	Dec. 31, 2019
Common Stock, Capital Shares Reserved for Future Issuance (in shares)	5,909,400
Convertible Preferred Stock [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)	5,296,800
Warrant [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)	612,600
Equity Option [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)