Quarterly report pursuant to Section 13 or 15(d)

Marketable Securities (Narrative) (Details)

Marketable Securities (Narrative) (Details) - Corporate Bonds [Member]
Sep. 30, 2018
USD ($)
Schedule of Available-for-sale Securities [Line Items]  
Securities in a loss position, less than one year | item 6
Fair value, less than one year $ 5,974,460
Unrealized losses, less than one year $ 26,899
Securities in a loss position, greater than one year | item 2
Fair value, greater than one year $ 1,999,550
Unrealized losses, greater than one year $ 2,588