Note 6 - Fair Value Measurement - Schedule of Fair Value Measurement of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Jun. 30, 2022
Debt Securities, Available-for-sale	$ 27,919	$ 26,173
Corporate & Government Debt Mutual Funds Securities [Member]
Debt Securities, Available-for-sale	18,965	19,191
Corporate & Government Debt ETFs Securities [Member]
Debt Securities, Available-for-sale	6,958	6,982
Interest-bearing Time Deposits [Member]
Debt Securities, Available-for-sale	1,996
Reported Value Measurement [Member]
Debt Securities, Available-for-sale	27,919	26,173
Reported Value Measurement [Member] | Corporate & Government Debt Mutual Funds Securities [Member] | Short-Term Investments [Member]
Debt Securities, Available-for-sale	18,965	19,191
Reported Value Measurement [Member] | Corporate & Government Debt ETFs Securities [Member] | Short-Term Investments [Member]
Debt Securities, Available-for-sale	6,958	6,982
Reported Value Measurement [Member] | Interest-bearing Time Deposits [Member] | Short-Term Investments [Member]
Debt Securities, Available-for-sale	1,996
Estimate of Fair Value Measurement [Member]
Debt Securities, Available-for-sale	27,919	26,173
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Debt Securities, Available-for-sale	25,923	26,173
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Debt Securities, Available-for-sale	1,996	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Debt Securities, Available-for-sale	0	0
Estimate of Fair Value Measurement [Member] | Corporate & Government Debt Mutual Funds Securities [Member] | Short-Term Investments [Member]
Debt Securities, Available-for-sale	18,965	19,191
Estimate of Fair Value Measurement [Member] | Corporate & Government Debt Mutual Funds Securities [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Debt Securities, Available-for-sale	18,965	19,191
Estimate of Fair Value Measurement [Member] | Corporate & Government Debt Mutual Funds Securities [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Debt Securities, Available-for-sale	0	0
Estimate of Fair Value Measurement [Member] | Corporate & Government Debt Mutual Funds Securities [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member]
Debt Securities, Available-for-sale	0	0
Estimate of Fair Value Measurement [Member] | Corporate & Government Debt ETFs Securities [Member] | Short-Term Investments [Member]
Debt Securities, Available-for-sale	6,958	6,982
Estimate of Fair Value Measurement [Member] | Corporate & Government Debt ETFs Securities [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Debt Securities, Available-for-sale	6,958	6,982
Estimate of Fair Value Measurement [Member] | Corporate & Government Debt ETFs Securities [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Debt Securities, Available-for-sale	0	0
Estimate of Fair Value Measurement [Member] | Corporate & Government Debt ETFs Securities [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member]
Debt Securities, Available-for-sale	0	$ 0
Estimate of Fair Value Measurement [Member] | Interest-bearing Time Deposits [Member] | Short-Term Investments [Member]
Debt Securities, Available-for-sale	1,996
Estimate of Fair Value Measurement [Member] | Interest-bearing Time Deposits [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Debt Securities, Available-for-sale	0
Estimate of Fair Value Measurement [Member] | Interest-bearing Time Deposits [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Debt Securities, Available-for-sale	1,996
Estimate of Fair Value Measurement [Member] | Interest-bearing Time Deposits [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member]
Debt Securities, Available-for-sale