Quarterly report pursuant to Section 13 or 15(d)

Investments - Schedule of Available-for-sale Securities Reconciliation (Details)

v3.7.0.1
Investments - Schedule of Available-for-sale Securities Reconciliation (Details) - USD ($)
6 Months Ended 12 Months Ended
Jun. 30, 2017
Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]    
Cost $ 1,566,000 $ 1,625,000
Unrealized Gain
Unrealized Loss (7,000) (11,000)
Fair Value 1,559,000 1,614,000
Short-term Investments [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Cost 20,000 115,000
Unrealized Gain
Unrealized Loss
Fair Value 20,000 115,000
Short-term Investments [Member] | Corporate Bonds and Commercial Paper [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Cost 20,000 25,000
Unrealized Gain
Unrealized Loss
Fair Value 20,000 25,000
Short-term Investments [Member] | U.S. Treasury Notes [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Cost   40,000
Unrealized Gain  
Unrealized Loss  
Fair Value   40,000
Short-term Investments [Member] | Government Agency Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Cost   50,000
Unrealized Gain  
Unrealized Loss  
Fair Value   50,000
Long-term Investments [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Cost 1,546,000 1,510,000
Unrealized Gain
Unrealized Loss (7,000) (11,000)
Fair Value 1,539,000 1,499,000
Long-term Investments [Member] | Corporate Bonds and Commercial Paper [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Cost 382,000 383,000
Unrealized Gain
Unrealized Loss (2,000) (3,000)
Fair Value 380,000 380,000
Long-term Investments [Member] | U.S. Treasury Notes [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Cost 1,064,000 1,027,000
Unrealized Gain
Unrealized Loss (4,000) (7,000)
Fair Value 1,060,000 1,020,000
Long-term Investments [Member] | Government Agency Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Cost 100,000 100,000
Unrealized Gain
Unrealized Loss (1,000) (1,000)
Fair Value $ 99,000 $ 99,000