Fair Value of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2016

Fair Value Disclosures [Abstract]

Schedule of fair value of financial assets and liabilities measured at fair value and classification by level of input

	Fair Value Measurements as of
	March 31, 2016
(in thousands)	Level 1		Level 2		Level 3		Total
Investments:
Money market funds	$	245	$	—	$	—	$	245
Total assets measured at fair value	$	245	$		$	—	$	245

	Fair Value Measurements as of
	December 31, 2015
(in thousands)	Level 1		Level 2		Level 3		Total
Investments:
Money market funds	$	196	$	—	$	—	$	196
Total assets measured at fair value	$	196	$	—	$	—	$	196

Schedule of changes in financial instruments measured at fair value using Level 3 inputs

	Fair Value Measurements of Level 3 Liabilities
	(in thousands)
Balance as of December 31, 2014	$	89
Loss on re-measurement of the financing derivative liability		3
Balance as of March 31, 2015		92
Loss on re-measurement of the financing derivative liability		135
Balance as of June 30, 2015		227
Loss on re-measurement of the financing derivative liability		114
Balance as of September 30, 2015		341
Loan payoff		(341	)
Balance as of December 31, 2015 and March 31, 2016	$	—