Note 7 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2020	Jul. 10, 2023	Jun. 30, 2021
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ (18)	$ 24
Liability for Uncertainty in Income Taxes, Current					$ 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	1,795
Capital Loss Carryforward [Member]
Tax Credit Carryforward, Amount				$ 2,343
Capital Loss Carryforward [Member] | Tax Year 2025 [Member]
Tax Credit Carryforward, Amount					271
Capital Loss Carryforward [Member] | Tax Year 2026 [Member]
Tax Credit Carryforward, Amount					1,152
Capital Loss Carryforward [Member] | Tax Year 2028 [Member]
Tax Credit Carryforward, Amount					$ 920
Domestic Tax Authority [Member]
Operating Loss Carryforwards	21,700
State and Local Jurisdiction [Member]
Operating Loss Carryforwards	$ 3,997
State and Local Jurisdiction [Member] | New Jersey Division of Taxation [Member] | CII [Member]
Income Tax Examination, Year under Examination		2016	2016 2017 2018 2019