Investments (Tables)

3 Months Ended

Mar. 31, 2018

Investments, Debt and Equity Securities [Abstract]

Schedule of the fair value of cash and cash equivalents and investments

The following table summarizes the fair value of cash and cash equivalents and investments as of December 31, 2017:

							Fair Value
Description	Cost		Level 1		Level 2		(Carrying Value)
Cash
Cash	$	2,544,972	$	2,544,972	$	—	$	2,544,972
Cash equivalents (maturity of 3 months or less)
Repurchase agreements		10,000,000		—		10,000,000		10,000,000
Money market funds		6,014,158		6,014,158		—		6,014,158
Cash and cash equivalents	$	18,559,130	$	8,559,130	$	10,000,000	$	18,559,130
Short-term investments (due within 1 year)
U.S. government treasury obligations	$	63,034,548	$	62,970,115	$	—	$	62,970,115
Corporate obligations		15,942,182		—		15,942,182		15,942,182
Total short-term investments	$	78,976,730	$	62,970,115	$	15,942,182	$	78,912,297

The following table summarizes the fair value of cash and cash equivalents and investments as of March 31, 2018:

							Fair Value
Description	Cost		Level 1		Level 2		(Carrying Value)
Cash
Cash	$	8,423,398	$	8,423,398	$	—	$	8,423,398
Cash equivalents (maturity of 3 months or less)
Repurchase agreements		10,000,000		—		10,000,000		10,000,000
Money market funds		16,993,446		16,993,446		—		16,993,446
U.S. government treasury obligations		34,955,020		34,956,700		—		34,956,700
Corporate obligations		19,459,253		—		19,458,200		19,458,200
Cash and cash equivalents	$	89,831,117	$	60,373,544	$	29,458,200	$	89,831,744
Short-term investments (due within 1 year)
U.S. government treasury obligations	$	56,621,253	$	56,550,250	$	—	$	56,550,250
Corporate obligations		26,751,400		—		26,742,633		26,742,633
Total short-term investments	$	83,372,653	$	56,550,250	$	26,742,633	$	83,292,883