Note 8 - Federal, State and Local Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Oct. 31, 2023	Apr. 30, 2023
Deferred tax liability	$ 12,537	$ 13,129
Domestic Tax Authority [Member]
Deferred gain on deconsolidation of EAM	10,669	10,669
Deferred non-cash post-employment compensation	(372)	(372)
Depreciation and amortization	53	59
Unrealized gain/(loss) on fixed income securities held for sale	(76)	99
Unrealized gain on equity securities	613	919
Right of Use Asset	(161)	(174)
Deferred charges	(144)	(136)
Other	(433)	(432)
Deferred tax liability	10,149	10,632
State and Local Jurisdiction [Member]
Deferred gain on deconsolidation of EAM	1,935	2,062
Deferred non-cash post-employment compensation	(67)	(72)
Depreciation and amortization	10	125
Unrealized gain/(loss) on fixed income securities held for sale	(13)	19
Unrealized gain on equity securities	111	178
Other	412	185
Deferred tax liability	$ 2,388	$ 2,497