Note 3 - Stockholders' Deficit, Stock Options and Warrants - Summary of Status of Options and Warrants Outstanding (Details) | 12 Months Ended |
Dec. 31, 2016$ / sharesshares |
Shares, options (in shares) | 165,643 |
Weighted average remaining life, options (Year) | |
Shares, warrants (in shares) | 871,101 |
Weighted average remaining life, warrants (Year) | |
Warrant One [Member] | |
Price, warrants (in dollars per share) | $ / shares | $ 4.46 |
Shares, warrants (in shares) | 756,999 |
Weighted average remaining life, warrants (Year) | 4 years 335 days |
Warrant Two [Member] | |
Price, warrants (in dollars per share) | $ / shares | $ 93.75 |
Shares, warrants (in shares) | 2,255 |
Weighted average remaining life, warrants (Year) | 1 year 69 days |
Warrant Three [Member] | |
Price, warrants (in dollars per share) | $ / shares | $ 123.75 |
Shares, warrants (in shares) | 94,085 |
Weighted average remaining life, warrants (Year) | 3 years 244 days |
Warrant Four [Member] | |
Price, warrants (in dollars per share) | $ / shares | $ 150 |
Shares, warrants (in shares) | 4,114 |
Weighted average remaining life, warrants (Year) | 1 year 73 days |
Warrant Five [Member] | |
Price, warrants (in dollars per share) | $ / shares | $ 225 |
Shares, warrants (in shares) | 107 |
Weighted average remaining life, warrants (Year) | 1 year 25 days |
Warrant Six [Member] | |
Price, warrants (in dollars per share) | $ / shares | $ 243.75 |
Shares, warrants (in shares) | 2,529 |
Weighted average remaining life, warrants (Year) | 2 years 215 days |
Warrant Seven [Member] | |
Price, warrants (in dollars per share) | $ / shares | $ 281.25 |
Shares, warrants (in shares) | 5,897 |
Weighted average remaining life, warrants (Year) | 346 days |
Warrant Eight [Member] | |
Price, warrants (in dollars per share) | $ / shares | $ 309.375 |
Shares, warrants (in shares) | 2,850 |
Weighted average remaining life, warrants (Year) | 2 years 222 days |
Warrant Nine [Member] | |
Price, warrants (in dollars per share) | $ / shares | $ 309.50 |
Shares, warrants (in shares) | 222 |
Weighted average remaining life, warrants (Year) | 2 years 310 days |
Warrant Ten [Member] | |
Price, warrants (in dollars per share) | $ / shares | $ 337.50 |
Shares, warrants (in shares) | 178 |
Weighted average remaining life, warrants (Year) | 1 year 167 days |
Warrant Eleven [Member] | |
Price, warrants (in dollars per share) | $ / shares | $ 371.25 |
Shares, warrants (in shares) | 944 |
Weighted average remaining life, warrants (Year) | 1 year 149 days |
Warrant Twelve [Member] | |
Price, warrants (in dollars per share) | $ / shares | $ 506.25 |
Shares, warrants (in shares) | 59 |
Weighted average remaining life, warrants (Year) | 2 years 43 days |
Warrant Thirteen [Member] | |
Price, warrants (in dollars per share) | $ / shares | $ 609.375 |
Shares, warrants (in shares) | 862 |
Weighted average remaining life, warrants (Year) | 2 years 32 days |
Stock Options One [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 2.25 |
Shares, options (in shares) | 293 |
Weighted average remaining life, options (Year) | 9 years 237 days |
Stock Options Two [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 2.42 |
Shares, options (in shares) | 37,152 |
Weighted average remaining life, options (Year) | 9 years 233 days |
Stock Options Three [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 2.80 |
Shares, options (in shares) | 57,145 |
Weighted average remaining life, options (Year) | 10 years |
Stock Options Four [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 3.75 |
Shares, options (in shares) | 44,000 |
Weighted average remaining life, options (Year) | 9 years 182 days |
Stock Options Five [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 4.125 |
Shares, options (in shares) | 3,636 |
Weighted average remaining life, options (Year) | 9 years 273 days |
Stock Options Six [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 4.1975 |
Shares, options (in shares) | 7,147 |
Weighted average remaining life, options (Year) | 9 years 262 days |
Stock Options Seven [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 4.25 |
Shares, options (in shares) | 3,529 |
Weighted average remaining life, options (Year) | 9 years 91 days |
Stock Options Eight [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 5.125 |
Shares, options (in shares) | 3,902 |
Weighted average remaining life, options (Year) | 9 years 251 days |
Stock Options Nine [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 65.75 |
Shares, options (in shares) | 342 |
Weighted average remaining life, options (Year) | 8 years 295 days |
Stock Options Ten [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 73.50 |
Shares, options (in shares) | 1,157 |
Weighted average remaining life, options (Year) | 9 years 3 days |
Stock Options Eleven [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 77.50 |
Shares, options (in shares) | 2,323 |
Weighted average remaining life, options (Year) | 8 years 182 days |
Stock Options Twelve [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 80.25 |
Shares, options (in shares) | 187 |
Weighted average remaining life, options (Year) | 8 years 273 days |
Stock Options Thirteen [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 86.25 |
Shares, options (in shares) | 232 |
Weighted average remaining life, options (Year) | 8 years 91 days |
Stock Options Fourteen [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 121.875 |
Shares, options (in shares) | 5 |
Weighted average remaining life, options (Year) | 6 years 73 days |
Stock Options Fifteen [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 131.25 |
Shares, options (in shares) | 81 |
Weighted average remaining life, options (Year) | 5 years 251 days |
Stock Options Sixteen [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 148.125 |
Shares, options (in shares) | 928 |
Weighted average remaining life, options (Year) | 6 years 76 days |
Stock Options Seventeen [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 150 |
Shares, options (in shares) | 1,760 |
Weighted average remaining life, options (Year) | 5 years 229 days |
Stock Options Eighteen [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 162.50 |
Shares, options (in shares) | 123 |
Weighted average remaining life, options (Year) | 8 years 3 days |
Stock Options Nineteen [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 206.25 |
Shares, options (in shares) | 121 |
Weighted average remaining life, options (Year) | 7 years 273 days |
Stock Options Twenty [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 248.4375 |
Shares, options (in shares) | 121 |
Weighted average remaining life, options (Year) | 6 years 197 days |
Stock Options Twenty One [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 262.50 |
Shares, options (in shares) | 130 |
Weighted average remaining life, options (Year) | 6 years 197 days |
Stock Options Twenty Two [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 281.25 |
Shares, options (in shares) | 529 |
Weighted average remaining life, options (Year) | 6 years 14 days |
Stock Options Twenty Three [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 318.75 |
Shares, options (in shares) | 3 |
Weighted average remaining life, options (Year) | 6 years 127 days |
Stock Options Twenty Four [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 346.875 |
Shares, options (in shares) | 72 |
Weighted average remaining life, options (Year) | 7 years 91 days |
Stock Options Twenty Five [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 431.25 |
Shares, options (in shares) | 306 |
Weighted average remaining life, options (Year) | 7 years 69 days |
Stock Options Twenty Six [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 468.75 |
Shares, options (in shares) | 133 |
Weighted average remaining life, options (Year) | 7 years 54 days |
Stock Options Twenty Seven [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 506.25 |
Shares, options (in shares) | 188 |
Weighted average remaining life, options (Year) | 7 years |
Stock Options Twenty Eight [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 543.75 |
Shares, options (in shares) | 53 |
Weighted average remaining life, options (Year) | 6 years 281 days |
Stock Options Twenty Nine [Member] | |
Range of exercise prices, options (in dollars per share) | $ / shares | $ 596.25 |
Shares, options (in shares) | 45 |
Weighted average remaining life, options (Year) | 6 years 273 days |