Note 3 - Basis of Presentation and Summary of Significant Accounting Policies - Outstanding Dilutive Securities (Details) - shares |
3 Months Ended | |
---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
|
Anti-dilutive securities (in shares) | 34,977,433 | 29,471,085 |
Convertible Debt Securities [Member] | ||
Anti-dilutive securities (in shares) | 214,880 | 766,351 |
Series A Convertible Preferred Stock [Member] | ||
Anti-dilutive securities (in shares) | 12,376,329 | |
Warrant [Member] | ||
Anti-dilutive securities (in shares) | 31,707,223 | 14,016,608 |
Employee Stock Option [Member] | ||
Anti-dilutive securities (in shares) | 3,053,797 | 2,304,132 |
Restricted Stock [Member] | ||
Anti-dilutive securities (in shares) | 1,533 | 7,665 |