Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($)	Mar. 31, 2022	Dec. 31, 2021
Accounts receivable, net of allowance for doubtful accounts	$ 25,000	$ 25,000
Mezzanine equity, liquidation preference	$ 23,469,000
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	2,000,000,000	2,000,000,000
Common stock, shares issued (in shares)	347,281,946	347,240,045
Common stock, shares outstanding (in shares)	347,275,242	347,233,341
Treasury stock, shares (in shares)	6,704	6,704
Mezzanine Equity Series D Convertible Redeemable Preferred Stock [Member]
Mezzanine equity, par value (in dollars per share)	$ 0.01	$ 0.01
Mezzanine equity, shares authorized (in shares)	26,000	26,000
Mezzanine equity, shares issued (in shares)	24,115	23,862
Mezzanine equity, shares outstanding (in shares)	23,469	23,216
Mezzanine equity, liquidation preference	$ 23,469,000	$ 23,216,000
Series B Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	750,000	750,000
Preferred stock, shares issued (in shares)	389,400	389,400
Preferred stock, shares outstanding (in shares)	239,400	239,400
Preferred stock, liquidation preference	$ 620	$ 607