Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2015

Fair Value Disclosures [Abstract]

Schedule of Marketable Securities

The following is a summary of available-for-sale marketable securities held as of September 30, 2015 and December 31, 2014 (in thousands):

			Gross Unrealized							Classification on Balance Sheet
	Amortized Cost		Gains		Losses			Aggregate Fair Value		Short-Term Marketable Securities		Long-Term Marketable Securities
As of September 30, 2015
Corporate bonds	$	1,017,036	$	668	$	(1,179	)	$	1,016,525	$	392,335	$	624,190
U.S. government agency obligations	230,598		257		(25		)	230,830		19,047		211,783
	$	1,247,634	$	925	$	(1,204	)	$	1,247,355	$	411,382	$	835,973
As of December 31, 2014
Certificates of deposit	$	39	$	—	$	—		$	39	$	—	$	39
Commercial paper	10,487		—		(2		)	10,485		10,485		—
Corporate bonds	1,077,387		454		(2,132		)	1,075,709		424,777		650,932
U.S. government agency obligations	303,808		20		(427		)	303,401		84,380		219,021
	$	1,391,721	$	474	$	(2,561	)	$	1,389,634	$	519,642	$	869,992

Schedule of Fair Value Measurement

The following table details the fair value measurements within the fair value hierarchy of the Company’s financial assets and liabilities at September 30, 2015 and December 31, 2014 (in thousands):

	Total Fair Value			Fair Value Measurements at Reporting Date Using
				Level 1		Level 2		Level 3
As of September 30, 2015
Cash Equivalents and Marketable Securities:
Money market funds	$	1,805		$	1,805	$	—	$	—
Corporate bonds	1,016,525			—		1,016,525		—
U.S. government agency obligations	230,830			—		230,830		—
Mutual funds	1,047			1,047		—		—
	$	1,250,207		$	2,852	$	1,247,355	$	—
As of December 31, 2014
Cash Equivalents and Marketable Securities:
Money market funds	$	501		$	501	$	—	$	—
Certificates of deposit	39			39		—		—
Commercial paper	10,485			—		10,485		—
Corporate bonds	1,075,709			—		1,075,709		—
U.S. government agency obligations	303,401			—		303,401		—
	$	1,390,135		$	540	$	1,389,595	$	—
Other Liabilities:
Contingent consideration obligation related to Velocius acquisition	$	(900	)	$	—	$	—	$	(900	)

Schedule of Liability Measured at Fair Value using Level 3 Inputs

The following table reflects the activity for the Company’s liability measured at fair value using Level 3 inputs for the nine months ended September 30, 2015 (in thousands):

	September 30, 2015
Balance as of January 1, 2015	$	(900	)
Fair value adjustment to contingent consideration included in general and administrative expense	(100		)
Achievement of final milestone related to Velocius contingent consideration	1,000
Balance as of September 30, 2015	$	—

Schedule of Contractual Maturities of Marketable Securities and Other Investment Related Assets

Contractual maturities of the Company’s available-for-sale marketable securities held at September 30, 2015 and December 31, 2014 were as follows (in thousands):

	September 30, 2015		December 31, 2014
Due in 1 year or less	$	411,382	$	519,642
Due after 1 year through 5 years	835,973		869,992
	$	1,247,355	$	1,389,634