Note 11 - Stockholders' Equity (Deficit) (Details Textual) | Aug. 01, 2016USD ($)shares | May 05, 2016USD ($)shares | Apr. 04, 2016USD ($)$ / sharesshares | Feb. 16, 2016USD ($)$ / sharesshares | Dec. 11, 2015 | Oct. 27, 2015USD ($)$ / sharesshares | Oct. 22, 2015 | May 22, 2015USD ($)$ / sharesshares | Mar. 06, 2015USD ($)$ / sharesshares | Oct. 16, 2014USD ($)shares | Mar. 25, 2014USD ($)$ / sharesshares | Oct. 31, 2015$ / sharesshares | May 31, 2015$ / sharesshares | Jul. 31, 2011$ / sharesshares | Dec. 31, 2016USD ($)$ / sharesshares | Sep. 30, 2016USD ($)shares | Sep. 30, 2016USD ($)shares | Sep. 29, 2016$ / shares | Dec. 31, 2016USD ($)$ / sharesshares | Dec. 31, 2015USD ($)$ / sharesshares | Dec. 31, 2014USD ($)$ / sharesshares | Sep. 28, 2016$ / shares | May 31, 2016shares | Feb. 29, 2016$ / shares | Mar. 03, 2015$ / shares | Dec. 31, 2013$ / shares |
Preferred Stock, Shares Authorized | | | | | | | | | | | | | | | 5,000,000 | | | | 5,000,000 | 5,000,000 | | | | | | |
Units Issued During Period | | | | | | | | | | | 224,000 | | | | | | | | | | | | | | | |
Common Stock Shares Per Unit | | | | | | | | | | | 1 | | | | | | | | | | | | | | | |
Warrants per Unit | | | | | | | | | | | 1 | | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right | | | | | | | | | | | 6.25 | | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | | | | | | | | | | | 56,000 | | | | 363,523 | 3,613,284 | 3,613,284 | | 363,523 | | | | 2,039,530 | | | |
Sale of Stock, Price Per Share | $ / shares | | | | | | $ 5 | | | | | $ 30 | | | | | | | | | | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | | | | | | | | | $ 39 | | | $ 33.25 | $ 1,810 | | | $ 3.15 | $ 1,810 | $ 5,190 | $ 35,230 | $ 19.50 | | | | $ 43,000 |
Warrant Date of Issuance of Term | | | | | | | | | | | 1 year 180 days | | | | | | | | | | | | | | | |
Proceeds from Issuance of Common Stock | $ | | | | | | $ 1,900,000 | | | $ 4,700,000 | | $ 6,700,000 | | | | | | | | $ 13,648,000 | $ 11,519,000 | $ 227,000 | | | | | |
Expense Related to Distribution or Servicing and Underwriting Fees | $ | | | | | | $ 400,000 | | | $ 200,000 | | 470,000 | | | | | | | | | | | | | | | |
Noninterest Expense Offering Cost | $ | | | | | | | | | | | 211,000 | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues | | | | 1,518,567 | | 492,000 | | 435,746 | | | | | | | | | | | | | | | | | | |
Investment Warrants, Exercise Price | $ / shares | | | | | | $ 5 | | | | | | $ 5 | | | | | | | | | | | | | | |
Class of Warrant or Right Issued During Period | | | | | | | | | | | | | | | | | | | 3,087 | 1,317 | 55 | | | | | |
Private Placement, Commission Percentage | | | 6.00% | 6.00% | | | | 6.00% | | | | | | | | | | | | | | | | | | |
Warrant Expiration Term | | | | | | 5 years | | | | | | 5 years | | | | | | | | | | | | | | |
Stock Issued During Period, Value, New Issues | $ | | | | $ 2,800,000 | | | | | | | | | | | | | | | | | | | | | | |
Common Stock, Par or Stated Value Per Share | $ / shares | | | | | | | | | | | | | | | $ 0.01 | | | | $ 0.01 | $ 0.01 | | | | | | |
Proceeds from Warrant Exercises | $ | | | | | | | | | | | | | | | $ 900,000 | $ 6,600,000 | | | | | | | | | | |
Class of Warrants or Rights, Exercises in Period | | | | | | | | | | | | | | | 363,523 | 3,613,284 | | | 3,977 | | | | | | | |
Warrants Exercised, Commission Percentage | | | | | | | | | | | | | | | 6.00% | 6.00% | 6.00% | | 6.00% | | | | | | | |
Warrants Exercised, Commission Paid | $ | | | | | | | | | | | | | | | $ 32,000 | $ 338,000 | $ 338,000 | | $ 32,000 | | | | | | | |
Noncash or Part Noncash Acquisition, Noncash Financial or Equity Instrument Consideration, Warrants Issued | | | | | | | | | | | | | | 139,520 | | | | | | | | | | | | |
Class of Warrant or Right, Exercise Price, Discount from Market Price | | | | | | | | | | | | | | | | | | 16.00% | | | | | | | | |
Fair Value Adjustment of Warrants | $ | | | | | | | | | | | | | | | | | | | $ 270,000 | | | | | | | |
Preferred Stock, Shares Outstanding | | | | | | | | | | | | | | | 0 | | | | 0 | 0 | | | | | | |
General and Administrative Expense [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Fair Value Adjustment of Warrants | $ | | | | | | | | | | | | | | | | | $ 270,000 | | | | | | | | | |
Maximum [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | | | | | | 468,280 | | | | | | 442,800 | | | | | | | | | | | | | | |
Long-term Warrants [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | | | | | | | | | | | | | | | | | | | | | | | $ 16.25 | |
Short-term Warrants [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | | | | | | | | | | | | | | | | | | | | | | | $ 15 | |
July 2011, March 2015, and October 2015 Warrants [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | | | | | | | | | | | | | | | 363,523 | 3,613,284 | 3,613,284 | | 363,523 | | | | | | | |
Proceeds from Warrant Exercises | $ | | | | | | | | | | | | | | | $ 900,000 | $ 6,900,000 | | | | | | | | | | |
Private Placement [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Units Issued During Period | | | | | | | | | 370,993 | | | | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | 1,047,121 | 2,039,530 | 3,086,651 | | | | | | 370,933 | | | | | | | | | | | | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | $ 1.91 | | | | | | | | | | | | | | | | | | | | | | | |
Warrant Date of Issuance of Term | | | | | | | | | | | | | 12 years | | | | | | | | | | | | | |
Proceeds from Issuance of Common Stock | $ | | | | | | | | $ 7,300,000 | | | | | | | | | | | | | | | | | | |
Expense Related to Distribution or Servicing and Underwriting Fees | $ | | | | | | | | $ 900,000 | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues | 2,094,241 | 4,079,058 | 6,173,299 | | | | | | | | | | | | | | | | | | | | | | | |
Unit Purchase Agreement Shares Per Unit | $ / shares | | | | | | | | $ 15.75 | | | | | | | | | | | | | | | | | | |
Investment Warrants, Exercise Price | $ / shares | | | | | | | | $ 19.50 | | | | | $ 19.50 | | | | | | | | | | | | | |
Class of Warrant or Right Issued During Period | | | | | | | | 217,873 | | | | | 217,873 | | | | | | | | | | | | | |
Warrant Expiration Term | | | 4 years | | | | | | | | | | | | | | | | | | | | | | | |
Common Stock, Par or Stated Value Per Share | $ / shares | | | $ 0.01 | | | | | | | | | | | | | | | | | | | | | | | |
Sale of Stock, Consideration Received on Transaction | $ | $ 4,000,000 | $ 7,800,000 | $ 11,800,000 | | | | | | | | | | | | | | | | | | | | | | | |
Number of Sequential Trading Days | | | 5 days | | | | | | | | | | | | | | | | | | | | | | | |
Number of Tranches for Private Placement | | | 2 | | | | | | | | | | | | | | | | | | | | | | | |
Private Placement [Member] | Minimum [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Common Stock, Closing Price | $ / shares | | | $ 4 | | | | | | | | | | | | | | | | | | | | | | | |
Private Placement [Member] | Outside Investors [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Unit Purchase Agreement Shares Per Unit | $ / shares | | | | | | | | | $ 12.50 | | | | | | | | | | | | | | | | | |
Private Placement [Member] | Company Insiders [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Unit Purchase Agreement Shares Per Unit | $ / shares | | | | | | | | | $ 15 | | | | | | | | | | | | | | | | | |
Private Placement [Member] | Long-term Warrants [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | | | | | | | | | 278,200 | | | | | | | | | | | | | | | | | |
Warrant Date of Issuance of Term | | | | | | | | | 5 years | | | | | | | | | | | | | | | | | |
Investment Warrants, Exercise Price | $ / shares | | | | | | | | | $ 16.25 | | | | | | | | | | | | | | | | | |
Warrant Expiration Term | | | | | | | 5 years | | | | | | | | | | | | | | | | | | | |
Private Placement [Member] | Short-term Warrants [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | | | | | | | | | 370,933 | | | | | | | | | | | | | | | | | |
Warrant Date of Issuance of Term | | | | | | | | | 1 year 90 days | | | | | | | | | | | | | | | | | |
Investment Warrants, Exercise Price | $ / shares | | | | | | | | | $ 15 | | | | | | | | | | | | | | | | | |
Warrant Expiration Term | | | | | | | 1 year 90 days | | | | | | | | | | | | | | | | | | | |
Mr. Fu [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues | | | | 696,590 | | | | | | | | | | | | | | | | | | | | | | |
Shares Issued, Price Per Share | $ / shares | | | | $ 1.81 | | | | | | | | | | | | | | | | | | | | | | |
Mr. Fu [Member] | July 2011, March 2015, and October 2015 Warrants [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | | | | | | | | | | | | | | | | | | | | | | $ 1.81 | | |
Shares Issued, Price Per Share | $ / shares | | | | | | | | | | | | | | | | | | | | | | | | $ 1.81 | | |
Pioneer Pharma Co. [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues | | | | 696,590 | | | | | | | | | | | | | | | | | | | | | | |
Shares Issued, Price Per Share | $ / shares | | | | $ 1.91 | | | | | | | | | | | | | | | | | | | | | | |
Mr. Sieczkarek [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues | | | | 125,387 | | | | | | | | | | | | | | | | | | | | | | |
Shares Issued, Price Per Share | $ / shares | | | | $ 1.91 | | | | | | | | | | | | | | | | | | | | | | |
Ascendiant Capital Markets [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Proceeds from Issuance of Common Stock | $ | | | | | | | | | | | | | | | | | | | | | 1,200,000 | | | | | |
Maximum Common Stock Aggregate Proceeds Pursuant to Offering Agreement | $ | | | | | | | | | | $ 10,000,000 | | | | | | | | | | | | | | | | |
Percent of Gross Proceeds on Common Stock Sold, Commissions | | | | | | | | | | 3.00% | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues | | | | | | | | | | 1,300,000 | | | | | | | | | | | | | | | | |
Sales Commissions and Fees | $ | | | | | | | | | | | | | | | | | | | | | 81,000 | | | | | |
China Kington Asset Management Co. Ltd. [Member] | Private Placement [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Payments of Stock Issuance Costs | $ | | | $ 618,000 | $ 155,000 | | | | $ 408,000 | | | | | | | | | | | | | | | | | | |
Net of Offering Costs and Commissions [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Proceeds from Issuance of Common Stock | $ | | | | | | $ 2,300,000 | | | $ 4,500,000 | | $ 6,000,000 | | | | | | | | | | | | | | | |
Net of Offering Costs and Commissions [Member] | Private Placement [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Proceeds from Issuance of Common Stock | $ | | | | | | | | $ 6,400,000 | | | | | | | | | | | | | | | | | | |
Net of Offering Costs and Commissions [Member] | Ascendiant Capital Markets [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Proceeds from Issuance of Common Stock | $ | | | | | | | | | | | | | | | | | | | | | $ 1,100,000 | | | | | |
In Exchange for Waiver [Member] | Private Placement [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues | | | | | | | | 635,000 | | | | | | | | | | | | | | | | | | |
Reverse Stock Split [Member] | | | | | | | | | | | | | | | | | | | | | | | | | | |
Stockholders' Equity Note, Stock Split, Conversion Ratio | | | | | 25 | | | | | | | | | | | | | | 25 | | | | | | | |