Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2014

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured at Fair Value on Recurring Basis

Assets and liabilities measured at fair value on a recurring basis as of March 31, 2014 and December 31, 2013 are summarized below (in thousands):

	March 31, 2014
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Direct or Indirect Observable Inputs (Level 2)		Total
Assets
Cash equivalents:
Money market funds	$	12,435	$	—	$	12,435
Corporate commercial paper		—		1,250		1,250
Corporate debt		—		652		652
Total cash equivalents		12,435		1,902		14,337
Short-term investments:
Corporate commercial paper		—		1,250		1,250
Corporate debt securities		—		4,881		4,881
Total short-term investments		—		6,131		6,131
Restricted cash—money market fund		250		—		250
Total assets measured at fair value	$	12,685	$	8,033	$	20,718

	December 31, 2013
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Direct or Indirect Observable Inputs (Level 2)		Total
Assets
Cash equivalents:
Money market funds	$	8,989	$	—	$	8,989
Corporate debt		—		2,000		2,000
Total cash equivalents		8,989		2,000		10,989
Short-term investments:
Corporate commercial paper		—		1,500		1,500
Foreign government bonds		—		1,001		1,001
Corporate debt securities		—		4,794		4,794
Total short-term investments		—		7,295		7,295
Restricted cash—money market fund		250		—		250
Total assets measured at fair value	$	9,239	$	9,295	$	18,534