Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2021

Fair Value Disclosures [Abstract]

Schedule of Financial Instruments Measured at Fair Value on Recurring Basis

The following tables set forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):

	March 31, 2021
	Total		Level 1 (Quoted Prices in Active Markets For Identical Assets)		Level 2 (Significant Other Observable Remaining Inputs)		Level 3 (Significant Other Unobservable Remaining Inputs)
Money market funds	$	362,762	$	362,762	$	-	$	-
U.S. treasury securities		206,460		-		206,460		-
U.S. government agency securities		5,002		-		5,002		-
Corporate securities and commercial paper		310,688		-		310,688		-
Total assets measured at fair value	$	884,912	$	362,762	$	522,150	$	-

	December 31, 2020
	Total		Level 1 (Quoted Prices in Active Markets For Identical Assets)		Level 2 (Significant Other Observable Remaining Inputs)		Level 3 (Significant Other Unobservable Remaining Inputs)
Money market funds	$	146,468	$	146,468	$	-	$	-
U.S. treasury securities		301,112		-		301,112		-
U.S. government agency obligations		25,001		-		25,001		-
Corporate securities and commercial paper		262,505		-		262,505		-
Total assets measured at fair value	$	735,086	$	146,468	$	588,618	$	-

Schedule of Investments Classified as Available for Sale Securities with Contractual Maturities

Classified as (with contractual maturities):

	March 31, 2021		December 31, 2020
Cash and cash equivalents	$	390,260	$	173,415
Short-term investments (due within one year)		436,666		555,231
Long-term investments (due between one and two years)		57,986		6,440
Total cash, cash equivalents and investments in marketable securities	$	884,912	$	735,086

Schedule of Fair Value and Amortized Cost of Investments in Marketable Securities by Major Security Type

The fair value and amortized cost of investments in marketable securities by major security type as of March 31, 2021 and December 31, 2020 are presented in the tables that follow (in thousands):

	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value
As of March 31, 2021:
Money market funds	$	362,762	$	-	$	-		$	362,762
U.S. treasury securities		206,422		40		(2	)		206,460
U.S. government agency securities		5,000		2		-			5,002
Corporate securities and commercial paper		310,730		14		(56	)		310,688
Total	$	884,914	$	56	$	(58	)	$	884,912

	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value
As of December 31, 2020:
Money market funds	$	146,468	$	-	$	-		$	146,468
U.S. treasury securities		301,075		38		(1	)		301,112
U.S. government agency obligations		24,997		4		-			25,001
Corporate securities and commercial paper		262,502		15		(12	)		262,505
Total	$	735,042	$	57	$	(13	)	$	735,086