Note 12 - Stock Repurchase Program (Details Textual) - USD ($)	12 Months Ended			290 Months Ended
	Jun. 30, 2019	Jun. 30, 2018		Jun. 30, 2019	Apr. 30, 1995
Stock Repurchase Program, Authorized Amount	$ 45,500,000			$ 45,500,000	$ 200,000
Stock Repurchased and Retired During Period, Shares	0	0		43,360,247
Cash Surrender Value of Life Insurance	$ 6,569,628	$ 6,374,372	[1]	$ 6,569,628
Estate of Former Chairman [Member]
Treasury Stock, Repurchase Price, Percentage of Fair Value of Common Stock	95.00%			95.00%
Stock Repurchase Program, Amount to Provide Proceeds Limitation	$ 2,500,000			$ 2,500,000
Percentage of Promissory Note Due To Execute A	25.00%			25.00%
Contingent Promissory Note Term	4 years
Cash Surrender Value of Life Insurance	$ 1,150,000			$ 1,150,000

[1] As adjusted for the retrospective adoption of ASC 606 and ASC 842