Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2016

Fair Value Disclosures [Abstract]

Schedule of Fair Value of Financial Liabilities

The 2016 Placement Warrants were issued in August and September 2016 and were outstanding at December 2016. The following table sets forth the fair value of the Company’s financial liabilities by level within the fair value hierarchy (in thousands):

	At December 31, 2016
	Level 1		Level 2		Level 3		Total
2016 Placement Warrants Liability	$	—	$	—	$	2,723	$	2,723

Summary of Changes in Fair Value of Level 3 Financial Liabilities

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

	Year Ended December 31,
	2016			2015			2014
Fair value, beginning of period	$	—		$	138		$	158
Issuance of 2016 Placement Warrants		2,726			—			—
Change in fair value of Level 3 financial    liabilities		(3	)		(45	)		(20	)
Conversion of convertible preferred stock    warrants to common stock warrants		—			(93	)		—
Fair value, end of period	$	2,723		$	—		$	138