Investments and Fair Value Measurement (Tables)

3 Months Ended

Mar. 31, 2013

Investments and Fair Value Measurement [Abstract]

Schedule of investments

The table below summarizes the Company’s investments (in thousands):

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized (Losses)		Estimated Fair  Value
March 31, 2013
Cash equivalents:
Money market funds	$	10,397	$	—	$	—	$	10,397
Total		10,397		—		—		10,397
Available-for-sale securities:
U.S. government sponsored entity debt securities		57,858		25		—		57,883
Corporate debt securities		0		—		—		0
Total		57,858		25		—		57,883
Total cash equivalents and available-for-sale securities	$	68,255	$	25	$	—	$	68,280
December 31, 2012
Cash equivalents:
U.S. government sponsored entity debt securities	$	2,997	$	—	$	—	$	2,997
Money market funds		15,839		—		—		15,839
Total		18,836		—		—		18,836
Available-for-sale securities:
U.S. government sponsored entity debt securities		54,426		26		—		54,452
Total		54,426		26		—		54,452
Total cash equivalents and available-for-sale securities	$	73,262	$	26	$	—	$	73,288

Summary of fair value measurements of cash equivalents and available-for-sale securities

The fair value measurements of our cash equivalents and available-for-sale securities are identified at the following levels within the fair value hierarchy (in thousands):

	March 31, 2013 Fair Value Measurements
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
Money market funds	$	10,397	$	10,397	$	—	$	—
Total		10,397		10,397		—		—
Available-for-sale securities:
U.S. government sponsored entity debt securities		57,883		—		57,883		—
Total		57,883		—		57,883		—
Total cash equivalents and available-for-sale securities	$	68,280	$	10,397	$	57,883	$	—

	December 31, 2012 Fair  Value Measurements
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
U.S. government sponsored entity debt securities	$	2,997	$	—	$	2,997	$	—
Money market funds		15,839		15,839		—		—
Total		18,836		15,839		2,997		—
Available-for-sale securities:
U.S. government sponsored entity debt securities		54,452		—		54,452		—
Total		54,452		—		54,452		—
Total cash equivalents and available-for-sale securities	$	73,288	$	15,839	$	57,449	$	—