Note 9 - Common Stock (Details Textual) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Common Stock, Shares Authorized	100,000,000	100,000,000
Common Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001
Common Stock, Shares, Issued	17,674,729	16,603,559
Common Stock, Shares, Outstanding	17,674,729	16,603,559