Investments (Tables)

12 Months Ended

Dec. 31, 2016

Investments, Debt and Equity Securities [Abstract]

Schedule 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, 2015:

							Fair Value
Description	Cost		Level 1		Level 2		(Carrying Value)
Cash
Cash	$	5,154,191	$	5,154,191	$	—	$	5,154,191
Cash equivalents
FDIC insured deposits and money market funds		10,277,431		10,277,431		—		10,277,431
Cash and cash equivalents	$	15,431,622	$	15,431,622	$	—	$	15,431,622
Short-term investments (due within 1 year)
U.S. government treasury obligations	$	73,593,081	$	73,560,085	$	—	$	73,560,085
U.S. government agency obligations		55,702,099		55,670,043		—		55,670,043
Corporate obligations		28,953,051		—		28,938,704		28,938,704
Total short-term investments	$	158,248,231	$	129,230,128	$	28,938,704	$	158,168,832

The following table summarizes the fair value of cash and cash equivalents and investments as of December: 31, 2016:  

							Fair Value
Description	Cost		Level 1		Level 2		(Carrying Value)
Cash
Cash	$	6,249,703	$	6,249,703	$	—	$	6,249,703
Cash equivalents
FDIC insured deposits and money market funds		24,978,489		24,978,489		—		24,978,489
Cash and cash equivalents	$	31,228,192	$	31,228,192	$	—	$	31,228,192
Short-term investments (due within 1 year)
U.S. government treasury obligations	$	86,078,622	$	86,053,755	$	—	$	86,053,755
Corporate obligations		20,941,799		—		20,925,469		20,925,469
Total short-term investments	$	107,020,420	$	86,053,755	$	20,925,469	$	106,979,224