Note 6 - Fair Value Measurement - Carrying Values and Fair Values (Details) - Fair Value, Inputs, Level 1 [Member] - US Treasury Bill Securities [Member] - USD ($) $ in Thousands	Sep. 30, 2022	Jun. 30, 2022
U.S. Treasury Bills	$ 35,123	$ 0
Reported Value Measurement [Member]
U.S. Treasury Bills	$ 35,123	$ 0