Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2016

Fair Value Disclosures [Abstract]

Schedule of fair value of the warrants

The fair value of the Warrants at September 30, 2016 was determined by using option pricing models with the following assumptions:

	Series C Warrants		Series A Warrants		February 2015 Warrants		October 2013 Warrants
Expected volatility		91.93%		96.65%		99.65%		91.70%
Risk-free interest rates		1.28%		1.01%		0.95%		0.76%
Expected life (in years)		5.70		3.81		3.38		2.08

Assets and liabilities measured at fair value on a recurring basis

The table below presents the Company’s assets and liabilities measured at fair value on a recurring basis as of September 30, 2016, aggregated by the level in the fair value hierarchy within which those measurements fall in accordance with ASC 820.

	Assets and Liabilities Measured at Fair Value on a Recurring Basis
(in thousands)	Level 1		Level 2		Level 3		Balance at September 30, 2016
Liabilities
Derivative instrument liabilities	$	—	$	—	$	22,502	$	22,502

Fair value measurements using significant unobservable inputs

The table below presents the activity within Level 3 of the fair value hierarchy for the nine months ended September 30, 2016:

Fair Value Measurements Using Significant Unobservable Inputs (Level 3)

(in thousands)	Warrant Liability
Balance at December 31, 2015	$	3,785
Total change in the liability included in earnings		(9,171	)
Fair value of warrants issued		28,133
Fair value of warrants exercised		(245	)
Balance at September 30, 2016	$	22,502