Note 2 - Investments - Investments With Fair Values Adjusted on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2023		Jun. 30, 2022
Statement [Line Items]
Investments in equity securities	$ 13,184		$ 14,300
Investments in debt securities	7,649	[1]	10,625
Fair Value, Recurring [Member]
Statement [Line Items]
Investments in equity securities	13,184		14,300
Investments in debt securities	7,649		10,625
Total investments carried at fair value	20,833		24,925
Fair Value, Nonrecurring [Member]
Statement [Line Items]
Total investments carried at fair value	1,634	[2]	781
Equity Securities International [Member]
Statement [Line Items]
Investments in equity securities	738		1,539
Equity Securities International [Member] | Fair Value, Recurring [Member]
Statement [Line Items]
Investments in equity securities	738		1,539
Mutual Funds Fixed Income [Member]
Statement [Line Items]
Investments in equity securities	11,701		12,138
Mutual Funds Fixed Income [Member] | Fair Value, Recurring [Member]
Statement [Line Items]
Investments in equity securities	11,701		12,138
Mutual Funds Global Equity [Member]
Statement [Line Items]
Investments in equity securities	745		623
Mutual Funds Global Equity [Member] | Fair Value, Recurring [Member]
Statement [Line Items]
Investments in equity securities	745		623
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Statement [Line Items]
Investments in equity securities	12,962		13,785
Investments in debt securities	0		0
Total investments carried at fair value	12,962		13,785
Fair Value, Inputs, Level 1 [Member] | Fair Value, Nonrecurring [Member]
Statement [Line Items]
Total investments carried at fair value	0	[2]	0
Fair Value, Inputs, Level 1 [Member] | Equity Securities International [Member] | Fair Value, Recurring [Member]
Statement [Line Items]
Investments in equity securities	516		1,024
Fair Value, Inputs, Level 1 [Member] | Mutual Funds Fixed Income [Member] | Fair Value, Recurring [Member]
Statement [Line Items]
Investments in equity securities	11,701		12,138
Fair Value, Inputs, Level 1 [Member] | Mutual Funds Global Equity [Member] | Fair Value, Recurring [Member]
Statement [Line Items]
Investments in equity securities	745		623
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Statement [Line Items]
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]
Statement [Line Items]
Total investments carried at fair value	0	[2]	0
Fair Value, Inputs, Level 2 [Member] | Equity Securities International [Member] | Fair Value, Recurring [Member]
Statement [Line Items]
Investments in equity securities	0		0
Fair Value, Inputs, Level 2 [Member] | Mutual Funds Fixed Income [Member] | Fair Value, Recurring [Member]
Statement [Line Items]
Investments in equity securities	0		0
Fair Value, Inputs, Level 2 [Member] | Mutual Funds Global Equity [Member] | Fair Value, Recurring [Member]
Statement [Line Items]
Investments in equity securities	0		0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Statement [Line Items]
Investments in equity securities	222		515
Investments in debt securities	7,649		10,625
Total investments carried at fair value	7,871		11,140
Fair Value, Inputs, Level 3 [Member] | Fair Value, Nonrecurring [Member]
Statement [Line Items]
Total investments carried at fair value	1,634	[2]	781
Fair Value, Inputs, Level 3 [Member] | Equity Securities International [Member] | Fair Value, Recurring [Member]
Statement [Line Items]
Investments in equity securities	222		515
Fair Value, Inputs, Level 3 [Member] | Mutual Funds Fixed Income [Member] | Fair Value, Recurring [Member]
Statement [Line Items]
Investments in equity securities	0		0
Fair Value, Inputs, Level 3 [Member] | Mutual Funds Global Equity [Member] | Fair Value, Recurring [Member]
Statement [Line Items]
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.