Annual report pursuant to Section 13 and 15(d)

Schedule of Fair Value Measurement of Assets and Liabilities (Details)

v3.21.1
Schedule of Fair Value Measurement of Assets and Liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities $ 46,247  
Cash and cash equivalents   $ 22,170
Total   27,775
Fair Value, Inputs, Level 1 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 18,429  
Cash and cash equivalents   22,170
Total   26,172
Fair Value, Inputs, Level 2 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 27,818  
Cash and cash equivalents   0
Total   1,603
Fair Value, Inputs, Level 3 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 0  
Cash and cash equivalents   0
Total   0
U.S. Treasury Bonds [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 18,429 4,002
U.S. Treasury Bonds [Member] | Fair Value, Inputs, Level 1 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 18,429 4,002
U.S. Treasury Bonds [Member] | Fair Value, Inputs, Level 2 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 0 0
U.S. Treasury Bonds [Member] | Fair Value, Inputs, Level 3 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 0 0
U.S. Government Notes [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 22,230  
U.S. Government Notes [Member] | Fair Value, Inputs, Level 1 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 0  
U.S. Government Notes [Member] | Fair Value, Inputs, Level 2 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 22,230  
U.S. Government Notes [Member] | Fair Value, Inputs, Level 3 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 0  
Corporate Debt Securities [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 4,306 1,603
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 0 0
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 4,306 1,603
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 0 $ 0
State and Municipal Bonds [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 1,282  
State and Municipal Bonds [Member] | Fair Value, Inputs, Level 1 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 0  
State and Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 1,282  
State and Municipal Bonds [Member] | Fair Value, Inputs, Level 3 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities $ 0