Quarterly report pursuant to Section 13 or 15(d)

Note 5 - Fair Value Measurements - Fair Value Measurements (Details)

v3.23.1
Note 5 - Fair Value Measurements - Fair Value Measurements (Details) - USD ($)
$ in Thousands
Mar. 31, 2023
Sep. 30, 2022
U.S Treasury securities $ 132,096  
Fair value 28,511  
U.S Treasury securities 28,511  
Certificates of Deposit [Member]    
Fair value 13,111  
U.S Treasury securities 13,111  
US Treasury Securities [Member]    
Fair value 15,400  
U.S Treasury securities 15,400  
Fair Value, Inputs, Level 1 [Member]    
U.S Treasury securities 18,212  
Fair value 0  
U.S Treasury securities 0  
Fair Value, Inputs, Level 1 [Member] | Certificates of Deposit [Member]    
Fair value 0  
U.S Treasury securities 0  
Fair Value, Inputs, Level 1 [Member] | US Treasury Securities [Member]    
Fair value 0  
U.S Treasury securities 0  
Fair Value, Inputs, Level 2 [Member]    
U.S Treasury securities 113,884  
Fair value 28,511  
U.S Treasury securities 28,511  
Fair Value, Inputs, Level 2 [Member] | Certificates of Deposit [Member]    
Fair value 13,111  
U.S Treasury securities 13,111  
Fair Value, Inputs, Level 2 [Member] | US Treasury Securities [Member]    
Fair value 15,400  
U.S Treasury securities 15,400  
Fair Value, Inputs, Level 3 [Member]    
U.S Treasury securities 0  
Fair value 0 $ 0
U.S Treasury securities 0 $ 0
Fair Value, Inputs, Level 3 [Member] | Certificates of Deposit [Member]    
Fair value 0  
U.S Treasury securities 0  
Fair Value, Inputs, Level 3 [Member] | US Treasury Securities [Member]    
Fair value 0  
U.S Treasury securities 0  
US Treasury Securities [Member]    
U.S Treasury securities 113,884  
US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]    
U.S Treasury securities 0  
US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]    
U.S Treasury securities 113,884  
US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]    
U.S Treasury securities 0  
Money Market Funds [Member]    
U.S Treasury securities 18,212  
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]    
U.S Treasury securities 18,212  
Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]    
U.S Treasury securities $ 0