Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2013

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 are summarized below (in thousands):

	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 fund	$	10,989	$	—	$	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	$	11,239	$	7,295	$	18,534

	December 31, 2012
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Direct or Indirect Observable Inputs (Level 2)		Total
Assets:
Cash equivalents—money market fund	$	7,313	$	—	$	7,313
Short-term investments:
Municipal securities		—		356		356
Corporate commercial paper		—		4,374		4,374
Foreign government bonds		—		999		999
Corporate debt securities		—		4,097		4,097
Total short-term investments		—		9,826		9,826
Restricted cash—money market fund		875		—		875
Total assets measured at fair value	$	8,188	$	9,826	$	18,014