Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Schedule of Marketable Securities

The following is a summary of available-for-sale marketable securities held as of December 31, 2019 and 2018 (in thousands):

			Gross Unrealized					Aggregate Fair Value		Classification on Balance Sheet
	Amortized Cost									Short-Term Marketable Securities		Long-Term Marketable Securities
As of December 31, 2019			Gains		Losses
Certificates of deposit	$	150,000	$	—	$	—		$	150,000	$	150,000	$	—
Commercial paper	73,829		23		(7		)	73,845		73,845		—
Corporate bonds	1,368,668		1,840		(378		)	1,370,130		753,538		616,592
U.S. government agency obligations	369,475		80		(74		)	369,481		165,623		203,858
	$	1,961,972	$	1,943	$	(459	)	$	1,963,456	$	1,143,006	$	820,450
As of December 31, 2018
Certificates of deposit	$	40,000	$	—	$	(7	)	$	39,993	$	39,993	$	—
Commercial paper	282,996		—		(50		)	282,946		282,946		—
Corporate bonds	685,653		1		(4,309		)	681,345		482,088		199,257
U.S. government agency obligations	50,876		—		(404		)	50,472		50,472		—
	$	1,059,525	$	1	$	(4,770	)	$	1,054,756	$	855,499	$	199,257

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 December 31, 2019 and 2018 (in thousands): 

	Total Fair Value			Fair Value Measurements at Reporting Date Using
				Level 1		Level 2		Level 3
As of December 31, 2019
Cash Equivalents and Marketable Securities:
Money market funds	$	50,779		$	50,779	$	—	$	—
Certificates of deposit	150,000			—		150,000		—
Commercial paper	73,845			—		73,845		—
Corporate bonds	1,370,130			—		1,370,130		—
U.S. government agency obligations	369,481			—		369,481		—
Mutual funds	15,177			15,177		—		—
	$	2,029,412		$	65,956	$	1,963,456	$	—
As of December 31, 2018
Cash Equivalents and Marketable Securities:
Money market funds	$	380,260		$	380,260	$	—	$	—
Certificates of deposit	39,993			39,993		—		—
Commercial paper	282,946			—		282,946		—
Corporate bonds	681,345			—		681,345		—
U.S. government agency obligations	50,472			—		50,472		—
Mutual funds	10,016			10,016		—		—
	$	1,445,032		$	430,269	$	1,014,763	$	—
Liabilities:
Contingent consideration obligation related to completed acquisitions	$	(6,300	)	$	—	$	—	$	(6,300	)

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 December 31, 2019 and 2018 were as follows (in thousands):

	December 31, 2019		December 31, 2018
Due in 1 year or less	$	1,143,006	$	855,499
Due after 1 year through 5 years	820,450		199,257
	$	1,963,456	$	1,054,756

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 for the years ended December 31, 2019 and 2018 (in thousands):

	2019			2018
Beginning balance	$	(6,300	)	$	(8,631	)
Fair value adjustment to contingent consideration included in general and administrative expense	—			(1,835		)
Cash paid upon achievement of milestone	6,300			4,166
Ending balance	$	—		$	(6,300	)