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SIGNIFICANT ACCOUNTING POLICIES - Amortized Cost Basis, Aggregate Fair Value, Unrealized (Gains)/Losses and Net Carrying Value of Investments in Held-to-maturity Securities (Details) - USD ($)
Mar. 31, 2019
Dec. 31, 2018
Schedule Of Held To Maturity Securities [Line Items]    
Marketable securities, Amortized Cost $ 48,556,558 $ 37,762,439
Marketable securities, Aggregate Fair Value 48,568,165 37,757,896
Marketable securities, Unrealized Gains   4,543
Marketable securities, Unrealized Losses (11,607)  
Marketable securities, Net Carrying Value 48,556,558 37,762,439
Corporate Bonds/Notes    
Schedule Of Held To Maturity Securities [Line Items]    
Marketable securities, Amortized Cost 10,823,308 16,054,071
Marketable securities, Aggregate Fair Value 10,832,228 16,050,462
Marketable securities, Unrealized Gains   3,609
Marketable securities, Unrealized Losses (8,920)  
Marketable securities, Net Carrying Value 10,823,308 16,054,071
Commercial Paper    
Schedule Of Held To Maturity Securities [Line Items]    
Marketable securities, Amortized Cost 25,819,617 17,756,394
Marketable securities, Aggregate Fair Value 25,819,617 17,756,394
Marketable securities, Net Carrying Value 25,819,617 17,756,394
U.S. government Agency Securities    
Schedule Of Held To Maturity Securities [Line Items]    
Marketable securities, Amortized Cost 11,913,633 3,951,974
Marketable securities, Aggregate Fair Value 11,916,320 3,951,040
Marketable securities, Unrealized Gains   934
Marketable securities, Unrealized Losses (2,687)  
Marketable securities, Net Carrying Value $ 11,913,633 $ 3,951,974