Quarterly report pursuant to Section 13 or 15(d)

Note 7 - Fair Value Measurements and Financial Instruments - Assets Measured on a Recurring Basis (Details)

v3.23.2
Note 7 - Fair Value Measurements and Financial Instruments - Assets Measured on a Recurring Basis (Details) - USD ($)
$ in Thousands
Jun. 30, 2023
Dec. 31, 2022
Assets, Fair Value Disclosure $ 20,727 $ 46,363
Level 1 [Member]    
Assets, Fair Value Disclosure 0 0
Level 2 [Member]    
Assets, Fair Value Disclosure 20,727 46,363
Level 3 [Member]    
Assets, Fair Value Disclosure 0 0
Money Market Accounts [Member]    
Assets, Fair Value Disclosure   165
Money Market Accounts [Member] | Level 1 [Member]    
Assets, Fair Value Disclosure   0
Money Market Accounts [Member] | Level 2 [Member]    
Assets, Fair Value Disclosure   165
Money Market Accounts [Member] | Level 3 [Member]    
Assets, Fair Value Disclosure   0
Money Market Funds [Member]    
Assets, Fair Value Disclosure 3,220 22,343
Money Market Funds [Member] | Level 1 [Member]    
Assets, Fair Value Disclosure 0 0
Money Market Funds [Member] | Level 2 [Member]    
Assets, Fair Value Disclosure 3,220 22,343
Money Market Funds [Member] | Level 3 [Member]    
Assets, Fair Value Disclosure 0 0
High Interest Savings Account [Member]    
Assets, Fair Value Disclosure 2,601 13,866
High Interest Savings Account [Member] | Level 1 [Member]    
Assets, Fair Value Disclosure 0 0
High Interest Savings Account [Member] | Level 2 [Member]    
Assets, Fair Value Disclosure 2,601 13,866
High Interest Savings Account [Member] | Level 3 [Member]    
Assets, Fair Value Disclosure 0 0
United States Treasury Bills [Member]    
Assets, Fair Value Disclosure   9,989
Short term investments 13,125  
United States Treasury Bills [Member] | Level 1 [Member]    
Assets, Fair Value Disclosure   0
Short term investments 0  
United States Treasury Bills [Member] | Level 2 [Member]    
Assets, Fair Value Disclosure   9,989
Short term investments 13,125  
United States Treasury Bills [Member] | Level 3 [Member]    
Assets, Fair Value Disclosure   $ 0
Short term investments 0  
Commercial Note [Member]    
Short term investments 1,781  
Commercial Note [Member] | Level 1 [Member]    
Short term investments 0  
Commercial Note [Member] | Level 2 [Member]    
Short term investments 1,781  
Commercial Note [Member] | Level 3 [Member]    
Short term investments $ 0