Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2017

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured at Fair Value on Recurring Basis

			Fair Value Measurements at June 30, 2017 Using
	June 30, 2017		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	$	245,036	$	245,036	$	—	$	—
Total	$	245,036	$	245,036	$	—	$	—
Liabilities:
Common stock warrants	$	41,099	$	—	$	—	$	41,099
Total	$	41,099	$	—	$	—	$	41,099

			Fair Value Measurements at December 31, 2016 Using
	December 31, 2016		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
Warrants:	Stock Price		Exercise Price		Expected Volatility		Risk-Free Interest		Expected Term	Dividends
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

	Black-Scholes Inputs to Warrant Liability Valuation at June 30, 2017
Warrants:	Stock Price		Exercise Price		Expected Volatility		Risk-Free Interest		Expected Term	Dividends
2014 Offering	$	2.69	$	5.60	69.05	%	1.37	%	2 years	none
2013 Offering	$	2.69	$	5.60	70.38	%	1.24	%	11 months	none

Summary of Changes in Fair Value of Company's Level 3 Financial Liabilities

The following table provides a summary of changes in the fair value of the Company’s Level 3 financial liabilities between December 31, 2016 and June 30, 2017.

	2014 Offering			2013 Offering			Total
Balance at December 31, 2016	$	4,112		$	529		$	4,641
Change in fair value of warrant liability from repricing (see Note 9)	177,999			66,612			244,611
Change in fair value of warrant liability	(147,158		)	(60,995		)	(208,153		)
Balance at June 30, 2017	$	34,953		$	6,146		$	41,099