Fair Value Measurement (Tables)

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

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

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

	December 31, 2015
	Fair Value Measurements
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
Money market funds	$	25,070	$	25,070	$	—	$	—
Commercial paper securities		2,000		2,000		—		—
U.S. government sponsored entity debt securities		38,867		38,867		—		—
Total		65,937		65,937		—		—
Marketable securities:
Commercial paper securities		30,717		—		30,717		—
Corporate debt securities		17,263		—		17,263		—
U.S. government sponsored entity debt securities		91,538		—		91,538		—
Total		139,518		—		139,518		—
Total cash equivalents and marketable securities	$	205,455	$	65,937	$	139,518	$	—

	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

The following sets forth the changes in the estimated fair value for our contingent consideration liability classified as Level 3 (in thousands):

Fair value as of December 31, 2013	$	1,570
Change in fair value		230
Fair value as of December 31, 2014		1,800
Change in fair value		(1,800	)
Fair value as of December 31, 2015	$	—