Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2018

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured at Fair Value on Recurring Basis

Assets measured at fair value on a recurring basis as of June 30, 2018 and December 31, 2017 are summarized below (in thousands):

	June 30, 2018						December 31, 2017
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Direct or Indirect Observable Inputs (Level 2)		Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Direct or Indirect Observable Inputs (Level 2)		Total
Assets
Cash equivalents:
Money market funds	$	1,717	$	—	$	1,717	$	2,274	$	—	$	2,274
Corporate commercial paper		—		500		500		—		3,245		3,245
Corporate debt		—		783		783		—		1,000		1,000
Total cash equivalents		1,717		1,283		3,000		2,274		4,245		6,519
Short-term investments:
Corporate commercial paper		—		3,729		3,729		—		5,480		5,480
Corporate debt		—		3,894		3,894		—		6,415		6,415
Total short-term investments		—		7,623		7,623		—		11,895		11,895
Total assets measured at fair value	$	1,717	$	8,906	$	10,623	$	2,274	$	16,140	$	18,414