Note 3 - Basis of Presentation and Summary of Significant Accounting Policies - Outstanding Dilutive Securities (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Anti-dilutive securities (in shares)	2,290,748	768,557
Convertible Debt Securities [Member]
Anti-dilutive securities (in shares)		14,292
Warrant [Member]
Anti-dilutive securities (in shares)	2,087,012	29,848
Series A Convertible Preferred Stock [Member]
Anti-dilutive securities (in shares)		553,752
Employee Stock Option [Member]
Anti-dilutive securities (in shares)	203,736	170,461
Restricted Stock [Member]
Anti-dilutive securities (in shares)		204