Note 7 - Net Loss Per Common Share (Details Textual)	3 Months Ended
	Mar. 31, 2018 shares
Share-based Payment Arrangement, Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	3,300,000
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	6,700,000
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	338,000