Fair value of financial instruments (Tables)

9 Months Ended

Sep. 30, 2016

Marketable Securities

Schedule of fair value of assets and liabilities measured on recurring basis

The following fair value hierarchy table presents information about each major category of our financial assets measured at fair value on a recurring basis as of September 30, 2016 (in thousands):

	Fair Value Measurement at Reporting Date Using:
	Quoted Prices in		Significant Other		Significant
	Active Markets for		Observable		Unobservable
	Identical Assets		Inputs		Inputs		Balance as of
	(Level 1)		(Level 2)		(Level 3)		September 30, 2016
Cash and cash equivalents	$	580,099	$	—	$	—	$	580,099
Corporate debt securities		—		136,486		—		136,486
Long term investment (Note 9)		55,745		—		—		55,745
Total assets	$	635,844	$	136,486	$	—	$	772,330

The following fair value hierarchy table presents information about each major category of our financial liabilities measured at fair value on a recurring basis as of September 30, 2016 (in thousands):

	Fair Value Measurement at Reporting Date Using:
	Quoted Prices in		Significant Other		Significant
	Active Markets for		Observable		Unobservable
	Identical Assets		Inputs		Inputs		Balance as of
	(Level 1)		(Level 2)		(Level 3)		September 30, 2016
Contingent consideration (Note 3)	$	—	$	—	$	298,000	$	298,000
Total liabilities	$	—	$	—	$	298,000	$	298,000

Schedule of rollforward of Level 3 liabilities

The following is a rollforward of our Level 3 liabilities (in thousands):

	Level 3
Balance at January 1, 2016	$	—
Initial recognition of contingent consideration		293,000
Contingent consideration earned during the period but not yet paid		(4,012)
Payments made during the period		(1,271)
Change in fair value of contingent consideration		10,283
Balance at September 30, 2016	$	298,000

Schedule of fair value of assets measured on recurring basis

The following fair value hierarchy table presents information about each major category of our financial assets measured at fair value on a recurring basis as of December 31, 2015 (in thousands):

	Fair Value Measurement at Reporting Date Using:
	Quoted Prices in		Significant Other		Significant
	Active Markets for		Observable		Unobservable
	Identical Assets		Inputs		Inputs		Balance as of
	(Level 1)		(Level 2)		(Level 3)		December 31, 2015
Cash and cash equivalents	$	521,439	$	—	$	—	$	521,439
Corporate debt securities		—		186,344		—		186,344
Long term investment (Note 9)		35,248		—		—		35,248
Total assets	$	556,687	$	186,344	$	—	$	743,031

Summary of marketable securities portfolio

The following is a summary of our marketable security portfolio as of September 30, 2016 and December 31, 2015, respectively.

			Net		Net
	Amortized		Unrealized		Unrealized		Estimated
	Cost		Gains		Losses		Fair Value
	(in thousands)
September 30, 2016
Corporate debt securities	$	136,082	$	404	$	—	$	136,486
December 31, 2015
Corporate debt securities	$	187,153	$	—	$	(809)	$	186,344