Note 3 - Investments - Investments With Fair Values Adjusted on Recurring Basis (Details) - USD ($) $ in Thousands		Dec. 31, 2023	Jun. 30, 2023
Investments in equity securities		$ 11,297	$ 13,205
Total investments in trading securities:		11,557	13,205
Investments in debt securities	[1]	5,784
Corporate Debt Securities [Member]
Corporate debt securities, fair value		260	0
Convertible Debt Securities [Member]
Investments in debt securities		5,784	7,008
Fair Value, Recurring [Member]
Total investments carried at fair value		17,341	20,213
Fair Value, Nonrecurring [Member]
Total investments carried at fair value	[2]	435	1,786
Equity Securities International [Member]
Investments in equity securities		445	778
Equity Securities International [Member] | Fair Value, Recurring [Member]
Investments in equity securities		445	778
Mutual Funds Fixed Income [Member]
Investments in equity securities		10,092	11,642
Mutual Funds Fixed Income [Member] | Fair Value, Recurring [Member]
Investments in equity securities		10,092	11,642
Mutual Funds Global Equity [Member]
Investments in equity securities		760	785
Mutual Funds Global Equity [Member] | Fair Value, Recurring [Member]
Investments in equity securities		760	785
Fair Value, Inputs, Level 1 [Member]
Investments in equity securities		11,295	12,915
Total investments in trading securities:		11,555	12,915
Fair Value, Inputs, Level 1 [Member] | Corporate Debt Securities [Member]
Corporate debt securities, fair value		260	0
Fair Value, Inputs, Level 1 [Member] | Convertible Debt Securities [Member]
Investments in debt securities		0	0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Total investments carried at fair value		11,555	12,915
Fair Value, Inputs, Level 1 [Member] | Fair Value, Nonrecurring [Member]
Total investments carried at fair value	[2]	0	0
Fair Value, Inputs, Level 1 [Member] | Equity Securities International [Member] | Fair Value, Recurring [Member]
Investments in equity securities		443	488
Fair Value, Inputs, Level 1 [Member] | Mutual Funds Fixed Income [Member] | Fair Value, Recurring [Member]
Investments in equity securities		10,092	11,642
Fair Value, Inputs, Level 1 [Member] | Mutual Funds Global Equity [Member] | Fair Value, Recurring [Member]
Investments in equity securities		760	785
Fair Value, Inputs, Level 2 [Member]
Investments in equity securities		0	0
Total investments in trading securities:		0	0
Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member]
Corporate debt securities, fair value		0	0
Fair Value, Inputs, Level 2 [Member] | Convertible Debt Securities [Member]
Investments in debt securities		0	0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Total investments carried at fair value		0	0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Nonrecurring [Member]
Total investments carried at fair value	[2]	0	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]
Investments in equity securities		2	290
Total investments in trading securities:		2	290
Fair Value, Inputs, Level 3 [Member] | Corporate Debt Securities [Member]
Corporate debt securities, fair value		0	0
Fair Value, Inputs, Level 3 [Member] | Convertible Debt Securities [Member]
Investments in debt securities		5,784	7,008
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Total investments carried at fair value		5,786	7,298
Fair Value, Inputs, Level 3 [Member] | Fair Value, Nonrecurring [Member]
Total investments carried at fair value	[2]	435	1,786
Fair Value, Inputs, Level 3 [Member] | Equity Securities International [Member] | Fair Value, Recurring [Member]
Investments in equity securities		2	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.