Note 2 - Investments - Assets and Liabilities (Details) - USD ($) $ in Thousands		Jan. 31, 2025	Oct. 31, 2024	Jul. 31, 2024	Apr. 30, 2024	Jan. 31, 2024	Oct. 31, 2023	Jul. 31, 2023	Apr. 30, 2023
EAM's total assets		$ 143,555			$ 136,035
EAM's total liabilities		44,605			45,242
EAM's total equity		98,950	$ 96,715	$ 93,854	90,793	$ 89,246	$ 85,742	$ 85,491	$ 83,673
EAM Trust [Member]
EAM's total assets		64,428			63,076
EAM's total liabilities	[1]	7,195			5,881
EAM's total equity		$ 57,233			$ 57,195

[1] At January 31, 2025 and April 30, 2024, EAM's total liabilities included a payable to VLI for its accrued non-voting revenues interest and non-voting profits interest of $4,855,000 and $3,865,000, respectively.