Note 1 - Description of Business and Basis of Presentation (Details Textual) - USD ($) |
9 Months Ended | |||||
|---|---|---|---|---|---|---|
Feb. 08, 2021 |
Feb. 04, 2021 |
Jan. 28, 2021 |
Sep. 30, 2021 |
Nov. 09, 2021 |
Nov. 04, 2021 |
|
| Subsequent Event [Member] | ||||||
| Equity Offering Sales Agreement, Aggregate Sales Price Value | $ 50,000,000.0 | |||||
| Common Stock [Member] | ||||||
| Stock Issued During Period, Shares, New Issues (in shares) | 2,530,000 | |||||
| The 2021 Offering [Member] | Lake Street Capital Markets, LLC and Northland Securities, Inc. [Member] | ||||||
| Proceeds from Issuance of Common Stock, Net | $ 27,600,000 | |||||
| The 2021 Offering [Member] | Lake Street Capital Markets, LLC and Northland Securities, Inc. [Member] | Common Stock [Member] | ||||||
| Stock Issued During Period, Shares, New Issues (in shares) | 2,530,000 | |||||
| Revolving Credit Facility [Member] | ||||||
| Debt Instrument, Collateral Amount | $ 750,000 | $ 1,500,000 | ||||
| Line of Credit Facility, Commitment Fee Percentage | 5.00% | |||||
| Revolving Credit Facility [Member] | Subsequent Event [Member] | ||||||
| Debt Instrument, Collateral Amount | $ 3,000,000 |