Fair Value of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2012

Fair Value of Financial Instruments [Abstract]

Summary of fair value measurement of financial instruments

The following table presents information about the Company’s financial instruments that are measured at fair value as of September 30, 2012 and indicates the fair value hierarchy of the valuation (in thousands):

	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Description
Cash equivalents:
Money market mutual funds	$	50,432	$	50,432	$	—	$	—

The following table presents information about the Company’s financial instruments that are measured at fair value as of December 31, 2011 and indicates the fair value hierarchy of the valuation (in thousands):

	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Description
Cash equivalents:
Money market mutual funds	$	4,201	$	4,201	$	—	$	—
Commercial paper		2,749		—		2,749		—
Total cash equivalents		6,950		4,201		2,749		—

	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Short-term investments:
Certificate of deposit		746		—		746		—
Municipal securities		33,592		—		33,592		—
Commercial paper		3,645		—		3,645		—
Corporate bonds		4,899		—		4,899		—
Total short-term investments		42,882		—		42,882		—
Cash equivalents and short-term investments	$	49,832	$	4,201	$	45,631	$	—