Quarterly report pursuant to Section 13 or 15(d)

Cash Equivalents and Investments (Schedule of Estimated Fair Value of Available-for-Sale Securities) (Details)

v3.20.2
Cash Equivalents and Investments (Schedule of Estimated Fair Value of Available-for-Sale Securities) (Details) - USD ($)
$ in Thousands
Jun. 30, 2020
Dec. 31, 2019
Schedule of Available-for-sale Securities [Line Items]    
Estimated Market Value $ 22,624 $ 18,461
Investments [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost, Due within one year 3,740  
Amortized Cost, Due after one year through five years 355  
Amortized Cost 4,095  
Estimated Market Value, Due within one year 3,748  
Estimated Market Value, Due after one year through five years 355  
Estimated Market Value $ 4,103 $ 9,700