Note 8 - Preferred Stock (Details Textual)	12 Months Ended
	Dec. 31, 2021 $ / shares shares	Dec. 31, 2011 shares	Jan. 25, 2022 $ / shares shares	Dec. 31, 2020 $ / shares shares
Preferred Stock, Shares Authorized (in shares)	2,445,598			2,445,598
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares	$ 0.01			$ 0.01
Preferred Stock, Shares Issued, Total (in shares)	2,445,598			2,445,598
Preferred Stock, Shares Outstanding, Ending Balance (in shares)	0			0
Series A Preferred Stock Converted into Common Stock [Member]
Conversion of Stock, Shares Converted (in shares)		554,402
Series A Preferred Stock [Member]
Preferred Stock, Shares Authorized (in shares)	3,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares	$ 0.01
Preferred Stock, Dividend Rate, Percentage	10.00%
Preferred Stock, Convertible, Conversion Ratio	1
Preferred Stock Number Of Authorized Shares Remaining (in shares)	2,445,598
Preferred Stock, Shares Issued, Total (in shares)	0			0
Preferred Stock, Shares Outstanding, Ending Balance (in shares)	0			0
Series B Preferred Stock [Member] | Subsequent Event [Member]
Preferred Stock, Shares Authorized (in shares)			2,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares			$ 1
Preferred Stock, Convertible, Conversion Ratio			1.5