Note 3 - Variable Interest Entity - Total Assets, the Maximum Exposure to Loss, and Value of the Assets and Liabilities in EAM (Details) - USD ($) $ in Thousands		Jan. 31, 2023	Apr. 30, 2022
Assets		$ 129,330	$ 128,743
Liabilities		47,104	49,098
EAM Trust [Member]
Assets		61,545	63,592
Liabilities	[1]	4,552	6,282
EAM Trust [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Assets	[2]	58,827	59,971
Liabilities		0	0
Value Line Maximum Exposure to Loss		$ 58,827	$ 59,971

[1] At July 31, 2022 and April 30, 2022, EAM's total liabilities included a payable to VLI for its accrued non-voting revenues interest and non-voting profits interest of $3,015,000 and $3,657,000, respectively.

[2] Reported within Long-Term Assets on Consolidated Balance Sheets.