Fair Value of Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2018

Fair Value Disclosures [Abstract]

Schedule of Fair Value of Financial Liabilities

The following table sets forth the fair value of the Company’s financial liabilities by level within the fair value hierarchy (in thousands):

	At June 30, 2018
	Level 1		Level 2		Level 3		Total
2017 Placement Warrants Liability	$	—	$	—	$	8,582	$	8,582
2016 Placement Warrants Liability		—		—		6,829		6,829
Total	$	—	$	—	$	15,411	$	15,411

	At December 31, 2017
	Level 1		Level 2		Level 3		Total
2017 Placement Warrants Liability	$	—	$	—	$	12,487	$	12,487
2016 Placement Warrants Liability		—		—		9,933		9,933
Total	$	—	$	—	$	22,420	$	22,420

Summary of Changes in Fair Value of Level 3 Financial Liabilities

The following table sets forth a summary of the changes in fair value of the Company’s Level 3 financial liabilities (in thousands):

	Six Months Ended June 30,
	2018			2017
Fair value, beginning of period	$	22,420		$	2,723
Issuance of 2017 Placement Warrants		—			3,373
Change in fair value of Level 3 financial liabilities		(7,009	)		9,032
Fair value, end of period	$	15,411		$	15,128