Note 10 - Stockholders' Equity (Details Textual) - USD ($)						12 Months Ended
	May 25, 2021	Mar. 23, 2021	Mar. 22, 2021	Apr. 25, 2020	Apr. 26, 2019	Dec. 31, 2021	Dec. 31, 2020
Share Exchange, Value Per Share (in dollars per share)				$ 0.44313
Preferred Stock, Par or Stated Value Per Share (in dollars per share)						$ 0.001	$ 0.001
Common Stock Dividends, Shares (in shares)	1,736,501
Common Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.001		$ 0.001			$ 0.001	$ 0.001
Shares Issued, Price Per Share (in dollars per share)	$ 0.44313		$ 0.853
Stock Issued During Period, Shares, New Issues (in shares)		3,517,000
Proceeds from Issuance of Private Placement		$ 3,000,000	$ 3,000,000.0		$ 27,500,000
Private Placement [Member]
Stock Issued During Period, Shares, New Issues (in shares)			3,517,000
Conversion of Series A Preferred Stock to Common Stock [Member]
Conversion of Stock, Shares Issued (in shares)						13,977,000	16,925,000
Conversion of Stock, Shares Converted (in shares)						61,937	750
Series A Preferred Stock [Member]
Preferred Stock, Dividend Rate, Percentage				8.00%
Dividends, Total	$ 1,650,000			$ 1,650,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.001
Dividends, Cash, Total	$ 880,000
Series A Preferred Stock [Member] | Dividend Paid [Member]
Dividends, Cash, Total						$ 3,000