Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2013

Financial Assets Measured at Fair Value

Fair values determined by Level 3 inputs are unobservable data points for the asset or liability, and includes situations where there is little, if any, market activity for the asset or liability.

Description    (in thousands)	September 30, 2013		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	$	37,952	$	37,952	$	—	$	—
Marketable debt securities		4,005		—		4,005		—
Total	$	41,957	$	37,952	$	4,005	$	—

Description   (in thousands)	December 31, 2012		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	$	15,910	$	15,910	$	—	$	—
Marketable debt securities		9,028		—		9,028		—
Total	$	24,938	$	15,910	$	9,028	$	—

Marketable Securities

The following tables summarize the Company’s marketable securities at September 30, 2013 and December 31, 2012 (in thousands):

	September 30, 2013
Description	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
US Treasury Bills and Notes (due within 1 year)	$	2,002	$	1	$	—	$	2,003
US Treasury Bills and Notes (due after 1 year through 2 years)		2,000		2				2,002
Total	$	4,002	$	3	$	—	$	4,005

	December 31, 2012
Description	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
US Treasury Bills and Notes (due within 1 year)	$	9,022	$	6	$	—	$	9,028
Total	$	9,022	$	6	$	—	$	9,028