Quarterly report pursuant to Section 13 or 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
Mar. 31, 2021
Dec. 31, 2020
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities $ 37,284 $ 46,247
Fair Value, Inputs, Level 1 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 17,651 18,429
Fair Value, Inputs, Level 2 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 19,633 27,818
Fair Value, Inputs, Level 3 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities
U.S. Treasury Bonds [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 17,651 18,429
U.S. Treasury Bonds [Member] | Fair Value, Inputs, Level 1 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 17,651 18,429
U.S. Treasury Bonds [Member] | Fair Value, Inputs, Level 2 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities
U.S. Treasury Bonds [Member] | Fair Value, Inputs, Level 3 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities
U.S. Government Notes [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 14,287 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
U.S. Government Notes [Member] | Fair Value, Inputs, Level 2 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 14,287 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
Corporate Debt Securities [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 4,067 4,306
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 4,067 4,306
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities
State and Municipal Bonds [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 1,279 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
State and Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member]    
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]    
Marketable Securities 1,279 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