Note 4 - Investments - Components of Investments (Details) - USD ($)		Jun. 30, 2023		Jun. 30, 2022
Cost		$ 19,601,000		$ 19,967,000
Unrealized gains losses		(6,396,000)		(5,667,000)
Fair value		13,205,000		14,300,000
Amortized cost	[1]	7,729,000		8,576,000
Unrealized gains	[1]	1,707,000		4,588,000
Unrealized losses	[1]	(2,428,000)		(2,539,000)
Investments in debt securities	[1]	7,008,000	[2]	10,625,000
Cost	[3]	1,000,000		1,000,000
Unrealized gains	[3]	0		0
Unrealized losses	[3]	(232,000)		(133,000)
Fair value of HTM	[3]	768,000		867,000
Equity Securities International [Member]
Cost		6,679,000		6,680,000
Unrealized gains losses		(5,901,000)		(5,141,000)
Fair value		778,000		1,539,000
Equity Securities Domestic [Member]
Cost		45,000		45,000
Unrealized gains losses		(45,000)		(45,000)
Fair value		0		0
Mutual Funds Fixed Income [Member]
Cost		11,947,000		12,313,000
Unrealized gains losses		(305,000)		(175,000)
Fair value		11,642,000		12,138,000
Mutual Funds Global Equity [Member]
Cost		930,000		929,000
Unrealized gains losses		(145,000)		(306,000)
Fair value		$ 785,000		$ 623,000

[1] Changes in unrealized gains and losses are included in the statement of comprehensive income (loss), except for embedded derivatives. Changes in unrealized and realized gains and losses for embedded derivatives are included in earnings in the statement of operations.

[2] Principal payments of $750,000 are due quarterly with a final maturity in January 2026.

[3] Held-to-maturity debt instruments are carried at amortized cost, and the fair value is classified as Level 2 according to the fair value hierarchy.