Note 8 - Loss Per Share - Antidilutive Securities Excluded from the Diluted Calculations (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement, Option [Member]
Antidilutive Securities (in shares)	766,424	366,928
Warrant [Member]
Antidilutive Securities (in shares)	2,171,610	362,664
Convertible Debt Securities [Member]
Antidilutive Securities (in shares)	82,751	329,409
Series B Convertible Preferred Stock [Member]
Antidilutive Securities (in shares)	7,925	7,925
Series D Convertible Preferred Stock [Member]
Antidilutive Securities (in shares)	350,000
Series E Convertible Preferred Stock [Member]
Antidilutive Securities (in shares)	594,383