Note 7 - Common Stock (Details Textual) - $ / shares shares in Thousands	Jun. 30, 2018	Dec. 31, 2017	[1]	Oct. 05, 2017	Oct. 04, 2017
Common Stock, Shares Authorized	142,857	142,857		142,857	500,000
Common Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001

[1] Derived from the Company's audited consolidated financial statements as of December 31, 2017.