Note 11 - Stockholders' Equity (Details Textual)			3 Months Ended		9 Months Ended
	Jul. 15, 2021 $ / shares shares	Jun. 19, 2020 $ / shares shares	Sep. 30, 2021 $ / shares shares	Sep. 30, 2020 shares	Sep. 30, 2021 $ / shares shares	Sep. 30, 2020 shares	Dec. 31, 2020 $ / shares
Incremental Common Shares Attributable to Share-based Payment Arrangements, Total (in shares)			35,000	0	35,000	35,000
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares	$ 0.02		$ 0.02		$ 0.02		$ 0.02
Stock Issued During Period, Fractional Shares, Stock Splits (in shares)	0
Reverse Stock Split, Fractional Shares, Cash, Multiplier	0.70
Reverse Stock Split [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio	12
Rights Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)		19,500,000
Shares Issued, Price Per Share (in dollars per share) | $ / shares		$ 0.65
Restricted Stock [Member]
Stock Repurchased During Period, Shares (in shares)			0	0	0	0