Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2018

Fair Value Disclosures [Abstract]

Schedule of Financial Assets and Liabilities Measured at Fair Value

The following table presents our financial assets and liabilities that are carried at fair value (in thousands):

	Fair Value Measurement at June 30, 2018
	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents—money market funds	$	28,657	$	28,657	$	—	$	—
Restricted cash equivalents—money market fund		3,000		3,000		—		—
Total current assets		31,657		31,657		—		—
Restricted cash equivalents—money market fund		6,000		6,000		—		—
Total long term assets		6,000		6,000		—		—
Total assets	$	37,657	$	37,657	$	—	$	—
	Fair Value Measurement at December 31, 2017
	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents—money market funds	$	2,014	$	2,014	$	—	$	—
Cash equivalents—commercial paper		16,477		—		16,477		—
Cash equivalents—corporate bonds		1,457		—		1,457		—
Cash equivalents—U.S. government and agency securities		10,488		10,488		—		—
Restricted cash equivalents—money market fund		3,000		3,000		—		—
Restricted cash equivalents—U.S. government and agency security fund		8,987		8,987		—		—
Total current assets		42,423		24,489		17,934		—
Restricted cash equivalents—money market fund		6,000		6,000		—		—
Total long term assets		6,000		6,000		—		—
Total assets	$	48,423	$	30,489	$	17,934	$	—