Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2017

Fair Value Disclosures [Abstract]

Fair Value Measurements

The following tables present information about the Company’s assets and liabilities that are measured at fair value on a recurring basis for the periods presented and indicates the fair value hierarchy of the valuation techniques it utilized to determine such fair value. In general, fair values determined by Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities. Fair values determined by Level 2 inputs utilize data points that are observable such as quoted prices, interest rates, and yield curves. Fair values determined by Level 3 inputs are unobservable data points for the asset or liability, and include situations where there is little, if any, market activity for the asset or liability.

	December 31, 2017		Fair Value Measurements at December 31, 2017 Using
			Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	$	1,744,965	$	1,744,965	$	—	$	—
Total	$	1,744,965	$	1,744,965	$	—	$	—

	December 31, 2016		Fair Value Measurements at December 31, 2016 Using
			Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	$	833,831	$	833,831	$	—	$	—
Total	$	833,831	$	833,831	$	—	$	—
Liabilities:
Common stock warrants	$	4,641	$	—	$	—	$	4,641
Total	$	4,641	$	—	$	—	$	4,641

Black-Scholes Inputs to Warrant Liability Valuation

	Black-Scholes Inputs to Warrant Liability Valuation at December 31, 2016
	Stock Price		Exercise Price		Expected Volatility		Risk-Free Interest		Expected Term	Dividends
Warrants:
2014 Offering	$	5.92	$	65.28	64.19	%	1.33	%	2 years, 6 months	none
2013 Offering	$	5.92	$	64.00	71.61	%	0.99	%	1 year, 5 months	none

Fair Value, Liabilities Measured on Recurring Basis

The following table provides a summary of changes in the fair value of the Company’s Level 3 financial liabilities between December 31, 2015 and December 31, 2017.

	2014 Offering			2013 Offering			Total
Balance at December 31, 2015	$	227,992		$	52,311		$	280,303
Change in fair value of warrant liability	(223,880		)	(51,782		)	(275,662		)
Balance at December 31, 2016	$	4,112		$	529		$	4,641
Change in fair value of warrant liability from repricing (see Note 12)	177,999			66,612			244,611
Change in fair value of warrant liability	(147,278		)	(61,202		)	(208,480		)
Repurchase and retirement of warrants (see Note 12)	(34,833		)	(5,939		)	(40,772		)
Balance at December 31, 2017	$	—		$	—		$	—