Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2017

Fair Value Disclosures [Abstract]

Schedule of Marketable Securities

The following is a summary of available-for-sale marketable securities held as of September 30, 2017 and December 31, 2016 (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, 2017
Commercial paper	$	5,955	$	—	$	(2	)	$	5,953	$	5,953	$	—
Corporate bonds	815,357		337		(1,797		)	813,897		319,136		494,761
U.S. government agency obligations	220,013		—		(1,180		)	218,833		58,706		160,127
	$	1,041,325	$	337	$	(2,979	)	$	1,038,683	$	383,795	$	654,888
As of December 31, 2016
Commercial paper	$	40,965	$	—	$	(45	)	$	40,920	$	40,920	$	—
Corporate bonds	984,650		123		(3,697		)	981,076		418,495		562,581
U.S. government agency obligations	267,473		35		(1,366		)	266,142		53,157		212,985
	$	1,293,088	$	158	$	(5,108	)	$	1,288,138	$	512,572	$	775,566

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 as of September 30, 2017 and December 31, 2016 (in thousands):

	Total Fair Value			Fair Value Measurements at Reporting Date Using
				Level 1		Level 2		Level 3
As of September 30, 2017
Cash Equivalents and Marketable Securities:
Money market funds	$	26,201		$	26,201	$	—	$	—
Commercial paper	5,953			—		5,953		—
Corporate bonds	813,897			—		813,897		—
U.S. government agency obligations	218,833			—		218,833		—
Mutual funds	7,097			7,097		—		—
	$	1,071,981		$	33,298	$	1,038,683	$	—
Liabilities:
Contingent consideration obligations related to completed acquisitions	$	(5,300	)	$	—	$	—	$	(5,300	)
As of December 31, 2016
Cash Equivalents and Marketable Securities:
Money market funds	$	8,726		$	8,726	$	—	$	—
Commercial paper	40,920			—		40,920		—
Corporate bonds	981,076			—		981,076		—
U.S. government agency obligations	266,142			—		266,142		—
Mutual funds	4,022			4,022		—		—
	$	1,300,886		$	12,748	$	1,288,138	$	—
Liabilities:
Contingent consideration obligations related to completed acquisitions	$	(7,100	)	$	—	$	—	$	(7,100	)

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

Contractual maturities of the Company’s available-for-sale marketable securities held as of September 30, 2017 and December 31, 2016 were as follows (in thousands):

	September 30, 2017		December 31, 2016
Due in 1 year or less	$	383,795	$	512,572
Due after 1 year through 5 years	654,888		775,566
	$	1,038,683	$	1,288,138

Schedule of Activity of Major Classes of Assets Measured at Fair Value Using Level 3 Inputs

The following table reflects the activity for the Company’s major classes of liabilities measured at fair value using Level 3 inputs during the nine months ended September 30, 2017 (in thousands):

	Other Liabilities: Contingent Consideration Obligation
Balance as of January 1, 2017	$	(7,100	)
Fair value adjustment to contingent consideration included in general and administrative expense	550
Cash paid upon achievement of milestone	1,250
Balance as of September 30, 2017	$	(5,300	)