Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 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 March 31, 2018 and December 31, 2017 are summarized below (in thousands):

	March 31, 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	$	297	$	—	$	297	$	2,274	$	—	$	2,274
Corporate commercial paper		—		2,494		2,494		—		3,245		3,245
Corporate debt		—		—		—		—		1,000		1,000
Total cash equivalents		297		2,494		2,791		2,274		4,245		6,519
Short-term investments:
Corporate commercial paper		—		4,970		4,970		—		5,480		5,480
Corporate debt		—		5,773		5,773		—		6,415		6,415
Total short-term investments		—		10,743		10,743		—		11,895		11,895
Total assets measured at fair value	$	297	$	13,237	$	13,534	$	2,274	$	16,140	$	18,414