Fair Value Measurement (Tables)

3 Months Ended

Mar. 31, 2014

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Summary of Fair Value Measurements of Cash Equivalents, Available-for-Sale Securities and Contingent Consideration Liability

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

	March 31, 2014 Fair Value Measurements
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
Money market funds	$	7,234	$	7,234	$	—	$	—
U.S. government sponsored entity debt securities		116,991		—		116,991		—
Total		124,225		7,234		116,991		—
Liabilities:
Contingent consideration liability	$	1,620	$	—	$	—	$	1,620
Total		1,620		—		—		1,620
	December 31, 2013 Fair Value Measurements
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
Money market funds	$	6,934	$	6,934	$	—	$	—
U.S. government sponsored entity debt securities		121,290		—		121,290		—
Total		128,224		6,934		121,290		—
Liabilities:
Contingent consideration liability	$	1,570	$	—	$	—	$	1,570
Total		1,570		—		—		1,570

Schedule of Fair Value of Contingent Consideration Liability

During the three months ended March 31, 2014, the recognized amount of the liability for contingent consideration increased by $0.1 million primarily as the result of the passage of time.

Fair value as of December 31, 2013	$	1,570
Change in fair value		50
Fair value as of March 31, 2014	$	1,620