Fair value of financial instruments (Tables)

3 Months Ended

Mar. 31, 2017

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 March 31, 2017 (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)		March 31, 2017
Cash and cash equivalents	$	361,823	$	—	$	—	$	361,823
Debt securities (corporate and government)		—		150,132		—		150,132
Long term investments (Note 9)		19,871		138,451		—		158,322
Total assets	$	381,694	$	288,583	$	—	$	670,277

Schedule of rollforward of Level 3 liabilities

	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)		March 31, 2017
Contingent consideration (Note 3)	$	—	$	—	$	304,000	$	304,000
Total liabilities	$	—	$	—	$	304,000	$	304,000

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

	Level 3
Balance at January 1, 2017	$	301,000
Contingent consideration earned during the period but not yet paid		(4,356)
Change in fair value of contingent consideration		7,356
Balance at March 31, 2017	$	304,000

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, 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)		December 31, 2016
Cash and cash equivalents	$	652,343	$	—	$	—	$	652,343
Debt securities (corporate and government)		—		156,203		—		156,203
Long term investment (Note 9)		31,987		—		—		31,987
Total assets	$	684,330	$	156,203	$	—	$	840,533

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 of December 31, 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)		December 31, 2016
Contingent consideration (Note 3)	$	—	$	—	$	301,000	$	301,000
Total liabilities	$	—	$	—	$	301,000	$	301,000

Fair Value, Liabilities Measured on Recurring Basis [Table Text Block]

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 December 31, 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)		December 31, 2016
Contingent consideration (Note 3)	$	—	$	—	$	301,000	$	301,000
Total liabilities	$	—	$	—	$	301,000	$	301,000

Summary of marketable securities portfolio

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 December 31, 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)		December 31, 2016
Contingent consideration (Note 3)	$	—	$	—	$	301,000	$	301,000
Total liabilities	$	—	$	—	$	301,000	$	301,000

The following is a summary of our marketable security portfolio as of March 31, 2017 and December 31, 2016, respectively.

			Net		Net
	Amortized		Unrealized		Unrealized		Estimated
	Cost		Gains		Losses		Fair Value
	(in thousands)
March 31, 2017
Debt securities (corporate and government)	$	150,293	$	—	$	(161)	$	150,132
December 31, 2016
Debt securities (corporate and government)	$	156,330	$	—	$	(127)	$	156,203