Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2021

Summary of Fair Value of Financial Assets by Level

The following tables summarize the amortized costs, unrealized gains and losses and fair value of these financial assets by significant investment category and their levels within the fair value hierarchy (in thousands):


	September 30, 2021
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value		Level I		Level II		Level III
Financial Assets:
Cash Equivalents:
Money market funds	$	277,510	$	—	$	—	$	277,510	$	277,510	$	—	$	—



Marketable Securities:
Commercial paper	127,925		—		—		127,925		—		127,925		—
Certificate of deposits(1)	86,685		—		—		86,685		—		86,685		—
U.S. government notes	1,079,140		120		(205)		1,079,055		1,079,055		—		—
Corporate bonds	1,190,273		377		(533)		1,190,117		—		1,190,117		—
Agency securities	271,589		147		(19)		271,717		—		271,717		—
	2,755,612		644		(757)		2,755,499		1,079,055		1,676,444		—
Other Assets:
Money market funds - restricted	4,236		—		—		4,236		4,236		—		—
Total Financial Assets	$	3,037,358	$	644	$	(757)	$	3,037,245	$	1,360,801	$	1,676,444	$	—


	December 31, 2020
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value		Level I		Level II		Level III
Financial Assets:
Cash Equivalents:
Money market funds	$	438,854	$	—	$	—	$	438,854	$	438,854	$	—	$	—


Marketable Securities:
Commercial paper	51,211		—		—		51,211		—		51,211		—
Certificate of deposits(1)	50,136		3		—		50,139		—		50,139		—
U.S. government notes	523,320		187		(1)		523,506		523,506		—		—
Corporate bonds	878,484		1,167		(330)		879,321		—		879,321		—
Agency securities	475,132		343		(3)		475,472		—		475,472		—
	1,978,283		1,700		(334)		1,979,649		523,506		1,456,143		—
Other Assets:
Money market funds - restricted	4,235		—		—		4,235		4,235		—		—
Total Financial Assets	$	2,421,372	$	1,700	$	(334)	$	2,422,738	$	966,595	$	1,456,143	$	—

______________________

(1) As of September 30, 2021 and December 31, 2020, all of our certificates of deposits were domestic deposits.

Fair Value of Available-For-Sale Investments By Contractual Maturity

The fair values of available-for-sale marketable securities, by remaining contractual maturities, are as follows (in thousands):


	September 30, 2021
Due in 1 year or less	$	1,559,405
Due in 1 year through 2 years	1,196,094
Total marketable securities	$	2,755,499