Fair Value Instruments - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Asset included in:
Financial Assets	$ 33,718,411	$ 8,521,054
Cash and Cash Equivalents | Money Market Securities
Asset included in:
Financial Assets	6,105,380	8,521,054
Investments Available-for-sale at Fair Value | U.S. Government Obligations
Asset included in:
Financial Assets	9,995,100
Investments Available-for-sale at Fair Value | Corporate Debt Securities
Asset included in:
Financial Assets	17,617,931
Level 1
Asset included in:
Financial Assets	16,100,480	8,521,054
Level 1 | Cash and Cash Equivalents | Money Market Securities
Asset included in:
Financial Assets	6,105,380	$ 8,521,054
Level 1 | Investments Available-for-sale at Fair Value | U.S. Government Obligations
Asset included in:
Financial Assets	9,995,100
Level 2
Asset included in:
Financial Assets	17,617,931
Level 2 | Investments Available-for-sale at Fair Value | Corporate Debt Securities
Asset included in:
Financial Assets	$ 17,617,931