Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2015

Marketable Securities [Abstract]

Schedule of Marketable Securities

The following is a summary of available-for-sale marketable securities held as of March 31, 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 March 31, 2015
Commercial paper	$	10,492	$	1	$	—		$	10,493	$	10,493	$	—
Corporate bonds	931,055		1,383		(263		)	932,175		314,352		617,823
U.S. government agency obligations	239,408		146		(27		)	239,527		55,883		183,644
	$	1,180,955	$	1,530	$	(290	)	$	1,182,195	$	380,728	$	801,467
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 March 31, 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 March 31, 2015
Cash Equivalents and Marketable Securities:
Money market funds	$	872		$	872	$	—	$	—
Commercial paper	12,493			—		12,493		—
Corporate bonds	932,175			—		932,175		—
U.S. government agency obligations	239,527			—		239,527		—
Mutual funds	387			387		—		—
	$	1,185,454		$	1,259	$	1,184,195	$	—
Other Liabilities:
Contingent consideration obligation related to Velocius acquisition	$	(900	)	$	—	$	—	$	(900	)
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 Contractual Maturities of Marketable Securities and Other Investment Related Assets

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

	March 31, 2015		December 31, 2014
Due in 1 year or less	$	380,728	$	519,642
Due after 1 year through 5 years	801,467		869,992
	$	1,182,195	$	1,389,634