Fair Value - Schedule of Fair Value Assets Measured on Recurring Basis (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 21,913,385
Marketable securities	8,966,250	$ 18,413,000
Total		28,960,000
Fair Value Measurements, Recurring Basis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	16,176,000	10,548,000
Marketable securities	8,966,000	18,412,000
Total	25,142,000	28,960,000
Fair Value Measurements, Recurring Basis | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	16,176,000	10,548,000
Total	16,176,000	10,548,000
Fair Value Measurements, Recurring Basis | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	8,966,000	18,412,000
Total	$ 8,966,000	$ 18,412,000