Note 2 - Investments - Components of EAM's Investment Management Operations (Details) - USD ($) $ in Thousands		3 Months Ended						9 Months Ended
		Jan. 31, 2025	Oct. 31, 2024	Jul. 31, 2024	Jan. 31, 2024	Oct. 31, 2023	Jul. 31, 2023	Jan. 31, 2025	Jan. 31, 2024
Revenues		$ 8,967			$ 9,131			$ 26,692	$ 28,484
Value Line’s non-voting revenues interest		4,363			3,083			12,089	8,420
EAM's net income		5,163	$ 5,685	$ 5,887	5,885	$ 3,488	$ 4,859	16,735	14,232
EAM Trust [Member]
Other income		140			192			456	295
Investment management fee waivers and reimbursements		44			77			131	239
12b-1 fee waivers		23			24			69	72
Value Line’s non-voting revenues interest		4,363			3,083			12,089	8,420
EAM's net income	[1]	1,094			812			3,384	1,842
EAM Trust [Member] | Investment Advice [Member]
Revenues		8,382			6,320			23,724	17,388
EAM Trust [Member] | Distribution and Shareholder Service [Member]
Revenues		$ 2,080			$ 1,632			$ 6,032	$ 4,811

[1] Represents EAM's net income, after giving effect to Value Line’s non-voting revenues interest, but before distributions to voting profits interest holders and to the Company in respect of its 50% non-voting profits interest.