Annual report pursuant to Section 13 and 15(d)

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

v3.22.1
Note 8 - Fair Value Measurements and Financial Instruments - Assets Measured on a Recurring Basis (Details) - USD ($)
$ in Thousands
Dec. 31, 2021
Dec. 31, 2020
Assets, fair value $ 78,834 $ 122,064
Fair Value, Inputs, Level 1 [Member]    
Assets, fair value 0 0
Fair Value, Inputs, Level 2 [Member]    
Assets, fair value 78,834 122,064
Fair Value, Inputs, Level 3 [Member]    
Assets, fair value 0 0
Money Market Accounts [Member]    
Assets, fair value 17,974 668
Money Market Accounts [Member] | Fair Value, Inputs, Level 1 [Member]    
Assets, fair value 0 0
Money Market Accounts [Member] | Fair Value, Inputs, Level 2 [Member]    
Assets, fair value 17,974 668
Money Market Accounts [Member] | Fair Value, Inputs, Level 3 [Member]    
Assets, fair value 0 0
Money Market Funds [Member]    
Assets, fair value 15,801 44,000
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]    
Assets, fair value 0 0
Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]    
Assets, fair value 15,801 44,000
Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member]    
Assets, fair value 0 0
Bank Time Deposits [Member]    
Assets, fair value 5,045 48,397
Bank Time Deposits [Member] | Fair Value, Inputs, Level 1 [Member]    
Assets, fair value 0 0
Bank Time Deposits [Member] | Fair Value, Inputs, Level 2 [Member]    
Assets, fair value 5,045 48,397
Bank Time Deposits [Member] | Fair Value, Inputs, Level 3 [Member]    
Assets, fair value 0 0
Commercial Notes [Member]    
Assets, fair value 19,998  
Commercial Notes [Member] | Fair Value, Inputs, Level 1 [Member]    
Assets, fair value 0  
Commercial Notes [Member] | Fair Value, Inputs, Level 2 [Member]    
Assets, fair value 19,998  
Commercial Notes [Member] | Fair Value, Inputs, Level 3 [Member]    
Assets, fair value 0  
US Treasury Securities [Member]    
Assets, fair value   5,000
US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]    
Assets, fair value   0
US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]    
Assets, fair value   5,000
US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]    
Assets, fair value   0
Corporate Debt Securities [Member]    
Assets, fair value 20,016  
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]    
Assets, fair value  
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]    
Assets, fair value 20,016  
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]    
Assets, fair value  
Canadian Treasury Securities [Member]    
Assets, fair value   23,999
Canadian Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]    
Assets, fair value   0
Canadian Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]    
Assets, fair value   23,999
Canadian Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]    
Assets, fair value   $ 0