Annual report pursuant to Section 13 and 15(d)

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

v3.20.1
Cash Equivalents and Investments (Schedule of Cash Equivalents and Available-for-Sale Securities) (Details) - USD ($)
Dec. 31, 2019
Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost $ 18,462,000 $ 8,428,000
Gross Unrealized Gains
Gross Unrealized Losses (1,000)
Fair Value 18,461,000 8,428,000
Cash Equivalents 8,761,000 8,428,000
Short-Term Investments 9,449,650
Long-Term Investments 250,000
Cash Equivalents [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 8,761,000  
Gross Unrealized Gains  
Gross Unrealized Losses  
Fair Value 8,761,000  
Cash Equivalents 8,761,000  
Short-Term Investments  
Long-Term Investments  
Cash Equivalents [Member] | Money Market Funds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 8,761,000 8,428,000
Gross Unrealized Gains
Gross Unrealized Losses
Fair Value 8,761,000 8,428,000
Cash Equivalents 8,761,000 8,428,000
Short-Term Investments
Long-Term Investments
Investments [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 9,701,000  
Gross Unrealized Gains  
Gross Unrealized Losses (1,000)  
Fair Value 9,700,000  
Cash Equivalents  
Short-Term Investments 9,450,000  
Long-Term Investments 250,000  
Investments [Member] | Commercial Paper [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 8,695,000  
Gross Unrealized Gains  
Gross Unrealized Losses (1,000)  
Fair Value 8,694,000  
Cash Equivalents  
Short-Term Investments 8,694,000  
Long-Term Investments  
Investments [Member] | Corporate Notes/Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 756,000  
Gross Unrealized Gains  
Gross Unrealized Losses  
Fair Value 756,000  
Cash Equivalents  
Short-Term Investments 756,000  
Long-Term Investments  
Investments [Member] | Convertible Debt [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 250,000  
Gross Unrealized Gains  
Gross Unrealized Losses  
Fair Value 250,000  
Cash Equivalents  
Short-Term Investments  
Long-Term Investments $ 250,000