Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Schedule of Financial Assets and Liabilities at Fair value on a Recurring Basis

The Company measures the following financial assets at fair value on a recurring basis. There were no transfers between levels of the fair value hierarchy during any of the periods presented. The following tables set forth the Company’s financial assets and liabilities carried at fair value categorized using the lowest level of input applicable to each financial instrument as of December 31, 2019 and 2018 (in thousands):

			Quoted Prices
			in Active		Significant
			Markets for		Other		Significant
	Balance at		Identical		Observable		Unobservable
	December 31,		Assets		Inputs		Inputs
	2019		(Level 1)		(Level 2)		(Level 3)
Assets:
Cash	$	6,732	$	6,732	$	—	$	—
Money market funds		4,301		4,301		—		—
Restricted cash		180		180		—		—
	$	11,213	$	11,213	$	—	$	—
Liabilities:
Derivative liability	$	2,425	$	—	$	—	$	2,425
	$	2,425	$	—	$	—	$	2,425

			Quoted Prices
			in Active		Significant
			Markets for		Other		Significant
	Balance at		Identical		Observable		Unobservable
	December 31,		Assets		Inputs		Inputs
	2018		(Level 1)		(Level 2)		(Level 3)
Assets:
Cash	$	6,868	$	6,868	$	—	$	—
Money market funds	$	43,937		43,937		—		—
Restricted cash	$	180		180		—		—
	$	50,985	$	50,985	$	—	$	—
Liabilities:
Derivative liability	$	2,142	$	—	$	—	$	2,142
	$	2,142	$	—	$	—	$	2,142

Roll-Forward of Fair Value of Derivative Liability

The following table provides a roll-forward of the fair value of the derivative liability (in thousands):

Balance at December 31, 2018	$	2,142
Change in fair value of derivative liability, recorded as interest    expense		283
Balance at December 31, 2019	$	2,425