Note 7 - Stockholders' Equity (Details Textual)		3 Months Ended		6 Months Ended		12 Months Ended		18 Months Ended
	Jul. 01, 2014 $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) shares	Jun. 30, 2020 USD ($) $ / shares shares	Jun. 30, 2019 USD ($)	Dec. 31, 2020 USD ($) $ / shares shares
Common Stock Voting Rights Votes Per Share								1
Shares Held by Subsidiaries (in shares)		704,309	704,309	704,309	704,309			704,309
Proceeds from the Sale of Units | $				$ 360,000	$ 977,000
Payments of Stock Issuance Costs | $				31,000	87,200
Adjustments to Additional Paid in Capital, Warrant Issued | $				$ 2,500
Class of Warrant or Right, Outstanding (in shares)		21,300,000		21,300,000				21,300,000
Weighted Average Exercise Price for Outstanding Warrants (in dollars per share) | $ / shares				$ 0.74
Weighted Average Remaining Contractual Life for Outstanding Warrants (Year)				3 years 73 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value | $				$ 0	99,500
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount | $		$ 0		$ 0				$ 0
Warrants with Extended Expiration Dates [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares						$ 0.75
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		3,547,735		3,547,735				3,547,735
Modification of Warrants | $				$ 25,506
Interest Expense Related to the Modification of Warrants | $				$ 163,384
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)		36,000,000		36,000,000				36,000,000
Share-based Payment Arrangement, Expense | $		$ 0	$ 99,500	$ 0	$ 99,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)		0	390,000	0	390,000
Subscription Agreement [Member]
Share Price (in dollars per share) | $ / shares		$ 0.75		$ 0.75				$ 0.75
Number of Warrants Per Unit (in shares)		1		1				1
Warrant Component of Equity Unit, Number of Shares of Restricted Common Stock Called by Each Warrant (in shares)		1		1				1
Sale of Units, Number Of Units Issued (in shares)				720,000
Proceeds from the Sale of Units | $				$ 360,000
Proceeds from Sale of Units, Net of Commissions | $				329,000
Payments of Stock Issuance Costs | $				$ 31,000
Stock Issued During Period, Shares, New Issues (in shares)				720,000
Class of Warrant or Right, Issued During Period (in shares)				720,000
Warrant Fair Value Price Per Share (in dollars per share) | $ / shares		$ 0.05		$ 0.05				$ 0.05
Adjustments to Additional Paid in Capital, Warrant Issued | $				$ 16,856
Adjustments to Additional Paid in Capital, Other | $				343,144
Deferred Compensation, Converted to Units, Amount | $				37,961
Loan Payable Converted to Units, Amount | $				$ 32,833
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares		$ 0.50		$ 0.50				$ 0.50
Subscription Agreement [Member] | Restricted Stock [Member]
Number of Shares Per Unit (in shares)		1		1				1
Minimum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares		$ 0.60		$ 0.60				$ 0.60
Maximum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares		2		2				$ 2
Maximum [Member] | Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)								10 years
Employees and Consultants [Member] | Minimum [Member]
Share Price (in dollars per share) | $ / shares		$ 0.50		$ 0.50				$ 0.50
President [Member]
Number of Shares Per Unit (in shares)		1		1				1
Number of Warrants Per Unit (in shares)		1		1				1
Deferred Compensation, Converted to Units, Amount | $				$ 37,961
Deferred Compensation and Accounts Payable Converted to Units, Shares (in shares)				141,589
Deferred Compensation, Loan Payable, and Accounts Payable Converted to Units, Price Per Unit (in dollars per share) | $ / shares		$ 0.50		$ 0.50				$ 0.50
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)		1		1				1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares		$ 0.75		$ 0.75				$ 0.75
Debt Conversion, Original Debt, Amount | $				$ 32,833
Deferred Compensation, Loan Payable, and Accounts Payable Converted to Units, Shares (in shares)				141,589
President [Member] | Warrants Related to the Conversion of Deferred Compensation and Accounts Payable into Units [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares		$ 0.75		$ 0.75				$ 0.75
President [Member] | Share-based Payment Arrangement, Option [Member]
Share-based Payment Arrangement, Plan Modification, Incremental Cost | $				$ 8,775
Consultant [Member]
Class of Warrant or Right, Issued During Period (in shares)								50,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		50,000		50,000				50,000
Class of Warrant or Right, Issued During the Period, Value Issued for Expenses | $				$ 2,500
Consultant [Member] | Maximum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares		$ 0.90		$ 0.90				$ 0.90
Brokers [Member]
Class of Warrant or Right, Issued During Period (in shares)				96,996
Brokers [Member] | Warrants Issued as Commissions [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares		$ 0.75		$ 0.75				$ 0.75
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		96,996		96,996				96,996
Centerpoint [Member]
Shares Held by Subsidiaries (in shares)		704,309		704,309				704,309
Series B Preferred Stock [Member]
Preferred Stock, Shares Outstanding, Ending Balance (in shares)	200	200		200		200		200
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares	$ 0.01	$ 0.01		$ 0.01		$ 0.01		$ 0.01
Preferred Stock, Convertible Option Per Share (in dollars per share) | $ / shares	$ 2
Preferred Stock, Dividend Rate, Percentage	2.50%
Preferred Stock, Redemption Price Per Share (in dollars per share) | $ / shares	$ 100
Convertible Preferred Stock Redemption Period (Year)	3 years
Dividends, Preferred Stock, Total | $				$ 19,500		$ 2,000	$ 2,000
Subscription Agreement [Member]
Sale of Units, Number Of Units Issued (in shares)				720,000
Proceeds from the Sale of Units | $				$ 360,000
Proceeds from Sale of Units, Net of Commissions | $				329,000
Payments of Stock Issuance Costs | $				$ 31,000
Stock Issued During Period, Shares, New Issues (in shares)				720,000
Class of Warrant or Right, Issued During Period (in shares)				720,000