Fair value measurements (Tables)

9 Months Ended

Sep. 30, 2017

Recorded Amount of Assets and Liabilities Measured at Fair Value on Recurring Basis

The following table sets forth the Company’s assets and liabilities that are measured at fair value on a recurring basis as of September 30, 2017 and December 31, 2016 (in thousands):

Description	Total		Quoted prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
September 30, 2017
Assets:
Cash and cash equivalents	$	237,962	$	227,245	$	10,717	$	—
Marketable securities:
U.S. government agency securities and treasuries		886,186		—		886,186		—
Certificates of deposit		18,482		—		18,482		—
Total assets	$	1,142,630	$	227,245	$	915,385	$	—
Liabilities:
Contingent consideration	$	2,961	$	—	$	—	$	2,961
Total liabilities	$	2,961	$	—	$	—	$	2,961
December 31, 2016
Assets:
Cash and cash equivalents	$	278,887	$	278,887	$	—	$	—
Marketable securities:
U.S. government agency securities and treasuries		599,460		—		599,460		—
Certificates of deposit		6,483		—		6,483		—
Total assets	$	884,830	$	278,887	$	605,943	$	—
Liabilities:
Contingent consideration	$	7,756	$	—	$	—	$	7,756
Total liabilities	$	7,756	$	—	$	—	$	7,756

Roll-Forward of Fair Value of the Company's Contingent Consideration Obligations

The table below provides a roll-forward of fair value of the Company’s contingent consideration obligations, which include Level 3 inputs (in thousands):

	For the Nine Months Ended
	September 30, 2017
Fair value, beginning of period	$	7,756
Additions		—
Changes in fair value		205
Payments		(5,000	)
Fair value, end of period	$	2,961