Note 8 - Federal, State and Local Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Jan. 31, 2025	Apr. 30, 2024
Total federal tax liability	$ 13,848	$ 12,893
Domestic Tax Jurisdiction [Member]
Deferred gain on deconsolidation of EAM	10,669	10,669
Deferred non-cash post-employment compensation	(372)	(372)
Depreciation and amortization	107	73
Unrealized gain/(loss) on fixed income securities held for sale	1,323	916
Right of Use Asset	(123)	(128)
Deferred charges	(156)	(138)
Other	(14)	(424)
Total federal tax liability	11,434	10,596
Unrealized gain/(loss) on fixed income securities held for sale	1,323	916
State and Local Jurisdiction [Member]
Deferred gain on deconsolidation of EAM	2,291	2,073
Deferred non-cash post-employment compensation	(80)	(72)
Depreciation and amortization	23	13
Unrealized gain/(loss) on fixed income securities held for sale	284	178
Other	(104)	105
Total federal tax liability	2,414	2,297
Unrealized gain/(loss) on fixed income securities held for sale	$ 284	$ 178