Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis

The following table presents information about our assets and liabilities that are measured at fair value on a recurring basis, and indicates the fair value hierarchy of the valuation techniques we utilized to determine such fair value (in thousands):

March 31, 2018	Level 1		Level 2		Level 3		Total
Assets
Cash	$	1,133	$	—	$	—	$	1,133
Money market securities (cash equivalents)		3,032		—		—		3,032
Restricted cash (Note 7)		272		—		—		272
Total assets	$	4,437	$	—	$	—	$	4,437
Liabilities
Warrants	$	—	$	—	$	—	$	—

Summary of Cash, Cash Equivalents and Short-Term Investments

Cash, cash equivalents and short-term investments consist of the following (in thousands):

			Gross		Gross
	Amortized		Unrealized		Unrealized		Estimated
March 31, 2018	Cost		Gains		Losses		Fair Value
Cash	$	1,133	$	—	$	—	$	1,133
Money market securities		3,032		—		—		3,032
Total cash and cash equivalents	$	4,165	$	—	$	—	$	4,165
Money market securities (restricted cash)		272		—		—		272
Total restricted cash	$	272	$	—	$	—	$	272