Annual report pursuant to Section 13 and 15(d)

Note 6 - Fair Value Measurements and Financial Instruments - Assets Measured on a Recurring Basis (Details)

v3.19.1
Note 6 - Fair Value Measurements and Financial Instruments - Assets Measured on a Recurring Basis (Details) - Fair Value, Measurements, Recurring [Member] - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Assets, fair value $ 15,118 $ 8,204
Fair Value, Inputs, Level 1 [Member]    
Assets, fair value
Fair Value, Inputs, Level 2 [Member]    
Assets, fair value 15,118 8,204
Fair Value, Inputs, Level 3 [Member]    
Assets, fair value
Bank Time Deposits [Member]    
Assets, fair value 496  
Bank Time Deposits [Member] | Fair Value, Inputs, Level 1 [Member]    
Assets, fair value  
Bank Time Deposits [Member] | Fair Value, Inputs, Level 2 [Member]    
Assets, fair value 496  
Bank Time Deposits [Member] | Fair Value, Inputs, Level 3 [Member]    
Assets, fair value  
Debt Security, Government, Non-US [Member]    
Assets, fair value 5,991 2,003
Debt Security, Government, Non-US [Member] | Fair Value, Inputs, Level 1 [Member]    
Assets, fair value
Debt Security, Government, Non-US [Member] | Fair Value, Inputs, Level 2 [Member]    
Assets, fair value 5,991 2,003
Debt Security, Government, Non-US [Member] | Fair Value, Inputs, Level 3 [Member]    
Assets, fair value
US Treasury Securities [Member]    
Assets, fair value 3,989  
US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]    
Assets, fair value  
US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]    
Assets, fair value 3,989  
US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]    
Assets, fair value  
Corporate Debt Securities [Member]    
Assets, fair value   1,999
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   1,999
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]    
Assets, fair value  
Investments [Member]    
Assets, fair value 4,642 4,202
Investments [Member] | Fair Value, Inputs, Level 1 [Member]    
Assets, fair value
Investments [Member] | Fair Value, Inputs, Level 2 [Member]    
Assets, fair value 4,642 4,202
Investments [Member] | Fair Value, Inputs, Level 3 [Member]    
Assets, fair value