Annual report pursuant to Section 13 and 15(d)

Note 8 - Fair Value Measurements and Financial Instruments - Assets Measured on a Recurring Basis (Details)

v3.23.1
Note 8 - Fair Value Measurements and Financial Instruments - Assets Measured on a Recurring Basis (Details) - USD ($)
$ in Thousands
Dec. 31, 2022
Dec. 31, 2021
Assets, Fair Value Disclosure $ 46,363 $ 78,834
Level 1 [Member]    
Assets, Fair Value Disclosure 0 0
Level 2 [Member]    
Assets, Fair Value Disclosure 46,363 78,834
Level 3 [Member]    
Assets, Fair Value Disclosure 0 0
Money Market Accounts [Member]    
Assets, Fair Value Disclosure 165 17,974
Money Market Accounts [Member] | Level 1 [Member]    
Assets, Fair Value Disclosure 0 0
Money Market Accounts [Member] | Level 2 [Member]    
Assets, Fair Value Disclosure 165 17,974
Money Market Accounts [Member] | Level 3 [Member]    
Assets, Fair Value Disclosure 0 0
Money Market Funds [Member]    
Assets, Fair Value Disclosure 22,343 15,801
Money Market Funds [Member] | Level 1 [Member]    
Assets, Fair Value Disclosure 0 0
Money Market Funds [Member] | Level 2 [Member]    
Assets, Fair Value Disclosure 22,343 15,801
Money Market Funds [Member] | Level 3 [Member]    
Assets, Fair Value Disclosure 0 0
High Interest Savings Accounts [Member]    
Assets, Fair Value Disclosure 13,866 5,045
High Interest Savings Accounts [Member] | Level 1 [Member]    
Assets, Fair Value Disclosure 0 0
High Interest Savings Accounts [Member] | Level 2 [Member]    
Assets, Fair Value Disclosure 13,866 5,045
High Interest Savings Accounts [Member] | Level 3 [Member]    
Assets, Fair Value Disclosure 0 0
Commercial Notes [Member]    
Assets, Fair Value Disclosure   19,998
Commercial Notes [Member] | Level 1 [Member]    
Assets, Fair Value Disclosure   0
Commercial Notes [Member] | Level 2 [Member]    
Assets, Fair Value Disclosure   19,998
Commercial Notes [Member] | Level 3 [Member]    
Assets, Fair Value Disclosure   0
United States Treasury Bills [Member]    
Assets, Fair Value Disclosure 9,989  
United States Treasury Bills [Member] | Level 1 [Member]    
Assets, Fair Value Disclosure 0  
United States Treasury Bills [Member] | Level 2 [Member]    
Assets, Fair Value Disclosure 9,989  
United States Treasury Bills [Member] | Level 3 [Member]    
Assets, Fair Value Disclosure $ 0  
Guaranteed Investment Certificate [Member]    
Assets, Fair Value Disclosure   20,016
Guaranteed Investment Certificate [Member] | Level 1 [Member]    
Assets, Fair Value Disclosure   0
Guaranteed Investment Certificate [Member] | Level 2 [Member]    
Assets, Fair Value Disclosure   20,016
Guaranteed Investment Certificate [Member] | Level 3 [Member]    
Assets, Fair Value Disclosure   $ 0