Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2021

The following is a summary of available-for-sale marketable securities held as of December 31, 2021 and 2020 (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, 2021			Gains		Losses

Commercial paper	$	25,056	$	—	$	(24)	$	25,032	$	25,032	$	—
Corporate bonds	1,268,991		1,191		(4,275)		1,265,907		459,012		806,895

U.S. government agency obligations	316,728		3		(1,281)		315,450		56,530		258,920
	$	1,610,775	$	1,194	$	(5,580)	$	1,606,389	$	540,574	$	1,065,815

As of December 31, 2020

Commercial paper	$	46,931	$	13	$	(8)	$	46,936	$	46,936	$	—
Corporate bonds	1,628,462		9,482		(262)		1,637,682		607,403		1,030,279
Municipal securities	3,495		—		(6)		3,489		—		3,489
U.S. government agency obligations	435,653		329		(63)		435,919		89,951		345,968
	$	2,114,541	$	9,824	$	(339)	$	2,124,026	$	744,290	$	1,379,736

Fair Value Measurement Within Fair Value Hierarchy

The following table details the fair value measurements within the fair value hierarchy of the Company’s financial assets as of December 31, 2021 and 2020 (in thousands):


	Total Fair Value		Fair Value Measurements at Reporting Date Using
			Level 1		Level 2
As of December 31, 2021
Cash Equivalents and Marketable Securities:
Money market funds	$	109,313	$	109,313	$	—

Commercial paper	39,031		—		39,031
Corporate bonds	1,265,907		—		1,265,907

U.S. government agency obligations	315,450		—		315,450
Mutual funds	23,129		23,129		—
	$	1,752,830	$	132,442	$	1,620,388

As of December 31, 2020
Cash Equivalents and Marketable Securities:
Money market funds	$	74,417	$	74,417	$	—

Commercial paper	75,785		—		75,785
Corporate bonds	1,637,682		—		1,637,682
Municipal securities	3,489		—		3,489
U.S. government agency obligations	435,919		—		435,919
Mutual funds	19,932		19,932		—
	$	2,247,224	$	94,349	$	2,152,875

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, 2021 and 2020 were as follows (in thousands):


	December 31, 2021		December 31, 2020
Due in 1 year or less	$	540,574	$	744,290
Due after 1 year through 5 years	1,065,815		1,379,736
	$	1,606,389	$	2,124,026