Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2015

Fair Value Disclosures [Abstract]

Schedule of Marketable Securities

The following is a summary of available-for-sale marketable securities held as of June 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 June 30, 2015
Commercial paper	$	3,498	$	1	$	—		$	3,499	$	3,499	$	—
Corporate bonds	1,015,164		588		(1,124		)	1,014,628		335,212		679,416
U.S. government agency obligations	248,598		110		(47		)	248,661		47,344		201,317
	$	1,267,260	$	699	$	(1,171	)	$	1,266,788	$	386,055	$	880,733
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 June 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 June 30, 2015
Cash Equivalents and Marketable Securities:
Money market funds	$	524		$	524	$	—	$	—
Commercial paper	3,499			—		3,499		—
Corporate bonds	1,014,628			—		1,014,628		—
U.S. government agency obligations	248,661			—		248,661		—
Mutual funds	719			719		—		—
	$	1,268,031		$	1,243	$	1,266,788	$	—
Other Liabilities:
Contingent consideration obligation related to Velocius acquisition	$	(1,000	)	$	—	$	—	$	(1,000	)
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 six months ended June 30, 2015 (in thousands):

	June 30, 2015
Balance as of January 1, 2015	$	(900	)
Fair value adjustment to contingent consideration included in general and administrative expense	(100		)
Balance as of June 30, 2015	$	(1,000	)

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 June 30, 2015 and December 31, 2014 were as follows (in thousands):

	June 30, 2015		December 31, 2014
Due in 1 year or less	$	386,055	$	519,642
Due after 1 year through 5 years	880,733		869,992
	$	1,266,788	$	1,389,634