Note 6 - Convertible Promissory Note - Convertible Promissory Note (Details) - Convertible Debt [Member] - The July 2019 Note [Member] - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020	Jul. 23, 2019
Maturity Date	Jul. 31, 2022	Jul. 31, 2022
Stated Interest Rate	24.00%	24.00%	24.00%
Conversion Price (in dollars per share)	$ 1.80	$ 1.80
Face Value	$ 1,000,000	$ 1,000,000	$ 1,000,000
Remaining debt discount	(347,000)	(507,000)
Carrying Value	$ 653,000	$ 493,000