Quarterly report pursuant to Section 13 or 15(d)

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

v3.19.2
Cash Equivalents and Investments (Schedule of Cash Equivalents and Available-for-Sale Securities) (Details) - USD ($)
Jun. 30, 2019
Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost $ 13,541,000 $ 8,428,000
Gross Unrealized Losses 0  
Fair Value 13,541,000 8,428,000
Cash Equivalents 9,540,000 8,428,000
Short-Term Investments 4,000,974
Long-Term Investments
Cash Equivalents [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 9,540,000  
Fair Value 9,540,000  
Cash Equivalents 9,540,000  
Short-Term Investments  
Long-Term Investments  
Cash Equivalents [Member] | Money Market Funds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 9,540,000 8,428,000
Fair Value 9,540,000 8,428,000
Cash Equivalents 9,540,000 8,428,000
Short-Term Investments
Long-Term Investments
Investments [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 4,001,000  
Fair Value 4,001,000  
Short-Term Investments 4,001,000  
Long-Term Investments  
Investments [Member] | Commercial Paper [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 1,992,000  
Fair Value 1,992,000  
Short-Term Investments 1,992,000  
Long-Term Investments  
Investments [Member] | Corporate Notes/Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 2,009,000  
Fair Value 2,009,000  
Short-Term Investments 2,009,000  
Long-Term Investments