Fair Value Measurement (Tables)

3 Months Ended

Mar. 31, 2015

Fair Value Disclosures [Abstract]

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, 2015
	Fair Value Measurements
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
Money market funds	$	17,089	$	17,089	$	—	$	—
Total		17,089		17,089		—		—
Marketable securities:
Commercial paper securities		31,148		—		31,148		—
Corporate debt securities		23,266		—		23,266		—
U.S. government sponsored entity debt securities		146,055		—		146,055		—
Total		200,469		—		200,469		—
Total cash equivalents and marketable securities	$	217,558	$	17,089	$	200,469	$	—

	December 31, 2014
	Fair Value Measurements
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
Money market funds	$	3,182	$	3,182	$	—	$	—
Total		3,182		3,182		—		—
Marketable securities:
Commercial paper securities		33,748		—		33,748		—
Corporate debt securities		22,813		—		22,813		—
U.S. government sponsored entity debt securities		163,631		—		163,631		—
Total		220,192		—		220,192		—
Total cash equivalents and marketable securities	$	223,374	$	3,182	$	220,192	$	—
Liabilities:
Contingent consideration liability	$	1,800	$	—	$	—	$	1,800
Total	$	1,800	$	—	$	—	$	1,800

Schedule of Changes in Estimated Fair Value of Contingent Consideration Liability

Fair value as of December 31, 2014	$	1,800
Change in fair value		(1,800	)
Fair value as of March 31, 2015	$	-