Condensed Consolidated Statements of Cash Flows (Unaudited) (Parentheticals) - USD ($)	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Paycheck Protection Program CARES Act [Member]
Extinguishment of debt	$ 172,056
Conversion of Series H Preferred Stock Into Common Stock [Member]
Convertible preferred stock (in shares)		1,686
Conversion of stock, shares issued (in shares)		469,697
Conversion of Series I Preferred Stock Into Common Stock [Member]
Convertible preferred stock (in shares)		700
Conversion of stock, shares issued (in shares)		204,371
Stock Purchase Warrants First Issuance [Member]
Common stock issued (in shares)	145,866
Stock purchase warrants exercised (in shares)	188,668