Note 7 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	27.50%
Income Tax Expense (Benefit), Total	$ 354,000	$ 326,000
Tax Adjustments, Settlements, and Unusual Provisions	202,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	(590,000)	(278,000)
Liability for Uncertainty in Income Taxes, Current	0		$ 0
Income Tax Examination, Penalties and Interest Accrued, Total	0
Deferred Tax Assets Related to Net Operating Loss [Member]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	(455,000)	(185,000)
Expired in 2020 [Member]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration		$ 77,000
Domestic Tax Authority [Member]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	33,000,000
State and Local Jurisdiction [Member]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	$ 7,000,000
State and Local Jurisdiction [Member] | New Jersey Division of Taxation [Member]
Income Tax Examination, Year under Examination	2014 2015 2016 2017