Fair Value Measurements (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Liabilities:
Derivative financial instruments—warrants	$ 834,940	$ 3,297,077
Estimate of Fair Value Measurement
Assets:
Short-term Investments	23,978,022
Recurring basis | Estimate of Fair Value Measurement
Assets:
Money market fund	12,095,620	65,016,222
Total Assets	37,272,146	65,016,222
Liabilities:
Derivative financial instruments—warrants	834,940	3,297,077
Total Liabilities	834,940	3,297,077
Recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Assets:
Money market fund	12,095,620	65,016,222
Total Assets	12,095,620	65,016,222
Liabilities:
Derivative financial instruments—warrants	0	0
Total Liabilities	0	0
Recurring basis | Significant Other Observable Inputs (Level 2)
Assets:
Money market fund	0	0
Total Assets	25,176,526	0
Liabilities:
Derivative financial instruments—warrants	0	0
Total Liabilities	0	0
Recurring basis | Significant Unobservable Inputs (Level 3)
Assets:
Money market fund	0	0
Total Assets	0	0
Liabilities:
Derivative financial instruments—warrants	834,940	3,297,077
Total Liabilities	834,940	$ 3,297,077
Corporate Debt Securities | Estimate of Fair Value Measurement
Assets:
Short-term Investments	14,160,686
Corporate Debt Securities | Recurring basis
Assets:
Short-term Investments	14,160,686
Corporate Debt Securities | Recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Assets:
Short-term Investments	0
Corporate Debt Securities | Recurring basis | Significant Other Observable Inputs (Level 2)
Assets:
Short-term Investments	14,160,686
Corporate Debt Securities | Recurring basis | Significant Unobservable Inputs (Level 3)
Assets:
Short-term Investments	0
Commercial Paper | Estimate of Fair Value Measurement
Assets:
Short-term Investments	1,195,444
Commercial Paper | Recurring basis
Assets:
Short-term Investments	2,393,948
Commercial Paper | Recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Assets:
Short-term Investments	0
Commercial Paper | Recurring basis | Significant Other Observable Inputs (Level 2)
Assets:
Short-term Investments	2,393,948
Commercial Paper | Recurring basis | Significant Unobservable Inputs (Level 3)
Assets:
Short-term Investments	0
US Treasury Securities | Estimate of Fair Value Measurement
Assets:
Short-term Investments	8,621,892
US Treasury Securities | Recurring basis
Assets:
Short-term Investments	8,621,892
US Treasury Securities | Recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Assets:
Short-term Investments	0
US Treasury Securities | Recurring basis | Significant Other Observable Inputs (Level 2)
Assets:
Short-term Investments	8,621,892
US Treasury Securities | Recurring basis | Significant Unobservable Inputs (Level 3)
Assets:
Short-term Investments	0
Cash and Cash Equivalents | Commercial Paper | Recurring basis | Significant Other Observable Inputs (Level 2)
Assets:
Short-term Investments	$ 1,198,504