Fair value of financial instruments (Tables)

6 Months Ended

Jun. 30, 2019

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 (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)		June 30, 2019
Cash and cash equivalents	$	1,416,224	$	—	$	—	$	1,416,224
Debt securities (corporate and government)		—		279,631		—		279,631
Long term investments (Note 9)		115,563		—		—		115,563
Total assets	$	1,531,787	$	279,631	$	—	$	1,811,418

	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, 2018
Cash and cash equivalents	$	1,163,980	$	—	$	—	$	1,163,980
Debt securities (corporate and government)		—		274,343		—		274,343
Long term investment (Note 9)		99,199		—		—		99,199
Total assets	$	1,263,179	$	274,343	$	—	$	1,537,522

Schedule of fair value of liabilities measured on recurring basis

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 (in thousands):

	Fair Value Measurement at Reporting Date Using:
	Quoted Prices in		Significant Other		Significant
	Active Markets for		Observable		Unobservable
	Identical Liabilities		Inputs		Inputs		Balance as of
	(Level 1)		(Level 2)		(Level 3)		June 30, 2019
Acquisition-related contingent consideration	$	—	$	—	$	286,000	$	286,000
Total liabilities	$	—	$	—	$	286,000	$	286,000

	Fair Value Measurement at Reporting Date Using:
	Quoted Prices in		Significant Other		Significant
	Active Markets for		Observable		Unobservable
	Identical Liabilities		Inputs		Inputs		Balance as of
	(Level 1)		(Level 2)		(Level 3)		December 31, 2018
Acquisition-related contingent consideration	$	—	$	—	$	287,001	$	287,001
Total liabilities	$	—	$	—	$	287,001	$	287,001

Schedule of roll forward of Level 3 liabilities

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

Balance at January 1, 2019	$	287,001
Contingent consideration earned during the period but not yet paid		(7,608)
Payments made during the period		(6,672)
Change in fair value of contingent consideration		13,279
Balance at June 30, 2019	$	286,000

Summary of marketable securities portfolio

The following is a summary of our marketable security portfolio (in thousands):

			Net		Net
	Amortized		Unrealized		Unrealized		Estimated
	Cost		Gains		Losses		Fair Value
June 30, 2019
Debt securities (corporate and government)	$	279,553	$	78	$	—	$	279,631
December 31, 2018
Debt securities (corporate and government)	$	275,405	$	—	$	(1,062)	$	274,343