Note 3 - Investments - Investments With Fair Values Adjusted on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023		Jun. 30, 2023
Investments in equity securities	$ 11,920		$ 13,205
Investments in debt securities	6,343	[1]	7,008
Fair Value, Recurring [Member]
Investments in equity securities	11,920		13,205
Investments in debt securities	6,343		7,008
Total investments carried at fair value	18,263		20,213
Fair Value, Nonrecurring [Member]
Total investments carried at fair value	435	[2]	1,786
Equity Securities International [Member]
Investments in equity securities	425		778
Equity Securities International [Member] | Fair Value, Recurring [Member]
Investments in equity securities	425		778
Mutual Funds Fixed Income [Member]
Investments in equity securities	10,793		11,642
Mutual Funds Fixed Income [Member] | Fair Value, Recurring [Member]
Investments in equity securities	10,793		11,642
Mutual Funds Global Equity [Member]
Investments in equity securities	702		785
Mutual Funds Global Equity [Member] | Fair Value, Recurring [Member]
Investments in equity securities	702		785
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Investments in equity securities	11,916		12,915
Investments in debt securities	0		0
Total investments carried at fair value	11,916		12,915
Fair Value, Inputs, Level 1 [Member] | Fair Value, Nonrecurring [Member]
Total investments carried at fair value	0	[2]	0
Fair Value, Inputs, Level 1 [Member] | Equity Securities International [Member] | Fair Value, Recurring [Member]
Investments in equity securities	421		488
Fair Value, Inputs, Level 1 [Member] | Mutual Funds Fixed Income [Member] | Fair Value, Recurring [Member]
Investments in equity securities	10,793		11,642
Fair Value, Inputs, Level 1 [Member] | Mutual Funds Global Equity [Member] | Fair Value, Recurring [Member]
Investments in equity securities	702		785
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Investments in equity securities	0		0
Investments in debt securities	0		0
Total investments carried at fair value	0		0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Nonrecurring [Member]
Total investments carried at fair value	0	[2]	0
Fair Value, Inputs, Level 2 [Member] | Equity Securities International [Member] | Fair Value, Recurring [Member]
Investments in equity securities	0		0
Fair Value, Inputs, Level 2 [Member] | Mutual Funds Fixed Income [Member] | Fair Value, Recurring [Member]
Investments in equity securities	0		0
Fair Value, Inputs, Level 2 [Member] | Mutual Funds Global Equity [Member] | Fair Value, Recurring [Member]
Investments in equity securities	0		0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Investments in equity securities	4		290
Investments in debt securities	6,343		7,008
Total investments carried at fair value	6,347		7,298
Fair Value, Inputs, Level 3 [Member] | Fair Value, Nonrecurring [Member]
Total investments carried at fair value	435	[2]	1,786
Fair Value, Inputs, Level 3 [Member] | Equity Securities International [Member] | Fair Value, Recurring [Member]
Investments in equity securities	4		290
Fair Value, Inputs, Level 3 [Member] | Mutual Funds Fixed Income [Member] | Fair Value, Recurring [Member]
Investments in equity securities	0		0
Fair Value, Inputs, Level 3 [Member] | Mutual Funds Global Equity [Member] | Fair Value, Recurring [Member]
Investments in equity securities	$ 0		$ 0

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

[2] Other investments include equity securities without readily determinable fair values that were adjusted as a result of the measurement alternative on dates during the three months ended September 30, 2022. These securities are classified as level 3 due to the infrequency of the observable price changes and/or restrictions on the shares.