Note 14 - Stockholders Equity (Details Textual) | | | | | | 1 Months Ended | 3 Months Ended | 6 Months Ended | 12 Months Ended | 18 Months Ended | 24 Months Ended | 36 Months Ended | | | | | |
May 15, 2023 USD ($) shares | May 11, 2023 | May 11, 2023 | May 10, 2023 | Jul. 12, 2022 USD ($) $ / shares shares | Dec. 15, 2021 USD ($) $ / shares shares | Nov. 30, 2022 USD ($) $ / shares shares | Jul. 31, 2022 USD ($) shares | Nov. 30, 2017 shares | Nov. 30, 2010 | Jun. 30, 2023 USD ($) $ / shares shares | Mar. 31, 2023 USD ($) shares | Jun. 30, 2022 USD ($) $ / shares shares | Jun. 30, 2023 USD ($) $ / shares shares | Jun. 30, 2022 USD ($) $ / shares | Jun. 30, 2023 USD ($) $ / shares shares | Dec. 31, 2022 USD ($) $ / shares shares | Jun. 30, 2023 USD ($) $ / shares shares | Jun. 30, 2022 USD ($) | Jun. 30, 2023 $ / shares shares | May 31, 2023 USD ($) $ / shares | Dec. 31, 2021 shares | Jul. 13, 2021 $ / shares | Dec. 09, 2020 $ / shares | Jun. 16, 2020 USD ($) $ / shares shares |
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares | | | | | | | | | | | $ 0.0001 | | | $ 0.0001 | | $ 0.0001 | $ 0.0001 | $ 0.0001 | | $ 0.0001 | | | | $ 0.0001 | |
Proceeds from Issuance of Common Stock | | | | | | | | | | | | | | $ 1,109,000 | $ 272,000 | | | | | | | | | | |
Stock Issued During Period, Value, New Issues | | | | | | | | | | | $ 71,000 | $ 745,000 | $ 48,000 | | | | | | | | | | | | |
Proceeds from Issuance of Private Placement | | | | | | | | | | | | | | 1,633,000 | 0 | | | | | | | | | | |
Payments of Stock Issuance Costs | | | | | | | | | | | | | | $ 367,000 | | | | | | | | | | | |
Common Stock, Capital Shares Reserved for Future Issuance (in shares) | shares | | | | | | | | | | | 14,149,339 | | | 14,149,339 | | 14,149,339 | 6,378,417 | 14,149,339 | | 14,149,339 | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Payments | | | | | | | | | | | | | | $ 0 | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value | | | | | | | | | | | $ 0 | | $ 0 | $ 0 | $ 0 | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share) | $ / shares | | | | | | | | | | | $ 3.38 | | $ 10.05 | $ 2.89 | $ 20.10 | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested in Period, Fair Value | | | | | | | | | | | $ 322,000 | | $ 411,000 | $ 681,000 | $ 775,000 | | | | | | | | | | |
The 2010 Share Option Plan [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) | | | | | | | | | 10 years | 7 years | | | | | | | | | | | | | | | |
Common Stock, Capital Shares Reserved for Future Issuance (in shares) | shares | | | | | | | | | 2,738 | | | | | | | | 6,284 | | | | | | | | |
The 2019 Plan [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares) | shares | | | | | | | | | | | 30,000 | | | 30,000 | | 30,000 | | 30,000 | | 30,000 | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) | shares | | | | | | | | | | | 61,554 | | | 61,554 | | 61,554 | 18,715 | 61,554 | | 61,554 | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Increase in Authorized Shares, Percentage of Outstanding Stock Maximum | | | | | | | | | | | | | | 4% | | | | | | | | | | | |
Series A Preferred Stock [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Preferred Stock, Shares Outstanding (in shares) | shares | | | | | | | | | | | | | | | | | | | | | | 252,717 | | | |
Voting Preferred Stock [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Preferred Stock, Liquidation Preference Per Share (in dollars per share) | $ / shares | | | | | | | $ 30 | | | | | | | | | | | | | | | | | | |
Preferred Stock, Convertible, Conversion Ratio | | | | | | | 0.6667 | | | | | | | | | | | | | | | | | | |
Preferred Stock, Convertible, Volume Weighted Average Price Per Common Share (in dollars per share) | $ / shares | | | | | | | $ 18.75 | | | | | | | | | | | | | | | | | | |
Senior Preferred Stock [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Preferred Stock, Convertible, Conversion Ratio | 2.6667 | | | | | | | | | | | | | | | | | | | | | | | | |
Liquidation Preference, Multiplier | 2.50 | | | | | | | | | | | | | | | | | | | | | | | | |
Conversion Price, Benchmark, Multiplier | 2.75 | | | | | | | | | | | | | | | | | | | | | | | | |
Common Stock [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues (in shares) | shares | | | | | | | | | | | 118,729 | 224,378 | 26,667 | | | | | | | | | | | | |
Stock Issued During Period, Value, New Issues | | | | | | | | | | | $ 0 | $ 1,000 | $ 0 | | | | | | | | | | | | |
Equity Purchase Agreement [Member] | Lincoln Park [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Equity Purchase Agreement, Maximum Offering Amount | | | | | | | | | | | | | | | | | | | | | | | | | $ 31,000,000 |
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares | | | | | | | | | | | | | | | | | | | | | | | | | $ 0.0001 |
Equity Purchase Agreement, Maximum Shares Issuable (in shares) | shares | | | | | | | | | | | | | | | | | | | | | | | | | 517,560 |
Equity Agreement, Maximum Percentage of Stock Outstanding | | | | | | | | | | | | | | | | | | | | | | | | | 19.99% |
Equity Agreement, Minimum Average Purchase Price (in dollars per share) | $ / shares | | | | | | | | | | | | | | | | | | | | | | | | | $ 59.6325 |
Maximum Percentage of Outstanding Stock, Beneficial Ownership | | | | | | | | | | | | | | | | | | | | | | | | | 9.99% |
Stock Issued During Period, Shares, New Issues (in shares) | shares | | | | | | | | 20,000 | | | | | | | | | 26,666,000 | | | 229,139 | | | | | |
Shares Issued, Price Per Share (in dollars per share) | $ / shares | | | | | | | | | | | $ 40.50 | | | $ 40.50 | | $ 40.50 | | $ 40.50 | | $ 40.50 | | | | | |
Stock Issued During Period, Shares, Commitment Fee (in shares) | shares | | | | | | | | | | | | | | | | | | | | 13,971 | | | | | |
Stock Issued During Period, Value, Commitment Fee | | | | | | | | | | | | | | | | | | | $ 620,000 | | | | | | |
Deferred Offering Costs | | | | | | | | | | | | | $ 123,000 | | $ 123,000 | | $ 0 | | $ 123,000 | | | | | | |
Proceeds from Issuance of Common Stock | | | | | | | | $ 300,000 | | | | | | | | | $ 272,000 | | | | | | | | |
LPC Purchase Agreement 2022 [Member] | Lincoln Park [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Equity Purchase Agreement, Maximum Offering Amount | | | | | $ 11,000,000 | | | | | | | | | | | | | | | | | | | | |
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares | | | | | $ 0.0001 | | | | | | | | | | | | | | | | | | | | |
Equity Purchase Agreement, Maximum Shares Issuable (in shares) | shares | | | | | 858,224 | | | | | | | | | | | | | | | | | | | | |
Equity Agreement, Maximum Percentage of Stock Outstanding | | | | | 19.99% | | | | | | | | | | | | | | | | | | | | |
Maximum Percentage of Outstanding Stock, Beneficial Ownership | | | | | 9.99% | | | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues (in shares) | shares | | | | | 50,000 | | | | | | | | | 343,116 | | 780,000 | 433,336 | | | | | | | | |
Shares Issued, Price Per Share (in dollars per share) | $ / shares | | | | | | | | | | | $ 3.23 | | | $ 3.23 | | $ 3.23 | $ 4.54 | $ 3.23 | | $ 3.23 | | | $ 3.97 | | |
Stock Issued During Period, Shares, Commitment Fee (in shares) | shares | | | | | 45,701 | | | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Value, Commitment Fee | | | | | $ 330,000 | | | | | | | | | | | | | | | | | | | | |
Proceeds from Issuance of Common Stock | | | | | | | | | | | | | | | | | | $ 8,700,000 | | | | | | | |
Stock Issued During Period, Value, New Issues | | | | | $ 300,000 | | | | | | | | | $ 1,109,000 | | $ 3,100,000 | $ 1,970,000 | | | | | | | | |
The 2021 Private Placement [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Proceeds from Issuance of Private Placement | | | | | | $ 17,000,000 | | | | | | | | | | | | | | | | | | | |
Payments of Stock Issuance Costs | | | | | | $ 300,000 | | | | | | | | | | | | | | | | | | | |
The 2021 Private Placement [Member] | Convertible Preferred Stock [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues (in shares) | shares | | | | | | 252,717 | | | | | | | | | | | | | | | | | | | |
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares | | | | | | $ 0.0001 | | | | | | | | | | | | | | | | | | | |
The 2021 Private Placement [Member] | Common Stock [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues (in shares) | shares | | | | | | 653,894 | | | | | | | | | | | | | | | | | | | |
The 2022 Private Placement [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Proceeds from Issuance of Private Placement | | | | | | | $ 6,720,000 | | | | | | | | | | | | | | | | | | |
Payments of Stock Issuance Costs | | | | | | | $ 202,000 | | | | | | | | | | | | | | | | | | |
The 2022 Private Placement [Member] | Convertible Preferred Stock [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues (in shares) | shares | | | | | | | 3,185,000 | | | | | | | | | | | | | | | | | | |
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares | | | | | | | $ 0.0001 | | | | | | | | | | | | | | | | | | |
Preferred Stock, Convertible, Shares Issuable (in shares) | shares | | | | | | | 2,123,443 | | | | | | | | | | | | | | | | | | |
The 2022 Private Placement [Member] | Common Stock [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares | | | | | | | $ 0.0001 | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues (in shares) | shares | | | | | | | 116,668 | | | | | | | | | | | | | | | | | | |
Multi-Tranche Private Placement 2023 [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Equity Purchase Agreement, Maximum Offering Amount | | | | | | | | | | | | | | | | | | | | | $ 9,000,000 | | | | |
Equity Purchase Agreement, Minimum Aggregate Purchase Amount Per Tranche | | | | | | | | | | | | | | | | | | | | | $ 500,000 | | | | |
Multi-Tranche Private Placement 2023 [Member] | Senior Preferred Stock [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues (in shares) | shares | 280,899 | | | | | | | | | | | | | | | | | | | | | | | | |
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares | | | | | | | | | | | | | | | | | | | | | $ 0.0001 | | | | |
Proceeds from Issuance of Preferred Stock and Preference Stock | $ 2,000,000 | | | | | | | | | | | | | | | | | | | | | | | | |
Reverse Stock Split [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Stockholders' Equity Note, Stock Split, Conversion Ratio | | 15 | 15 | | | | | | | | | | | | | | | | | | | | | | |
Reverse Stock Split [Member] | Minimum [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Stockholders' Equity Note, Stock Split, Conversion Ratio | | | | 5 | | | | | | | | | | | | | | | | | | | | | |
Reverse Stock Split [Member] | Maximum [Member] | | | | | | | | | | | | | | | | | | | | | | | | | |
Stockholders' Equity Note, Stock Split, Conversion Ratio | | | | 15 | | | | | | | | | | | | | | | | | | | | | |