Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2023

Investments, Debt and Equity Securities [Abstract]

The Company’s marketable securities, which consist of highly liquid marketable debt securities, are classified as available-for-sale and are stated at fair value. The following tables summarize the Company’s marketable securities (in thousands):


As of December 31, 2023	Maturity (in years)	Amortized Cost		Unrealized Gains		Unrealized Losses		Estimated Fair Value
U.S. Treasury securities	1 or less	$	301,053	$	102	$	(530)	$	300,625
U.S. Government agency securities	1 or less	5,000		—		(2)		4,998
Negotiable certificates of deposit	1 or less	4,410		1		(4)		4,407

U.S. Treasury securities	1 - 2	98,701		600		(36)		99,265
Negotiable certificates of deposit	1 - 2	980		—		(6)		974

Total		$	410,144	$	703	$	(578)	$	410,269


As of December 31, 2022	Maturity (in years)	Amortized Cost		Unrealized Gains		Unrealized Losses		Estimated Fair Value
U.S. Treasury securities	1 or less	$	230,349	$	1	$	(2,283)	$	228,067
U.S. Government agency securities	1 or less	5,000		—		(34)		4,966
Negotiable certificates of deposit	1 or less	3,911		1		(57)		3,855
Corporate debt securities	1 or less	16,360		—		(286)		16,074
U.S. Treasury securities	1 - 2	16,919		—		(41)		16,878
Negotiable certificates of deposit	1 - 2	490		1		—		491

Total		$	273,029	$	3	$	(2,701)	$	270,331

Schedule of Available-for-sale Securities in an Unrealized Loss Position

The following table summarizes marketable securities in a continuous unrealized loss position for which an allowance for credit losses was not recorded (in thousands):


	Less Than 12 Months				12 Months or Greater				Total
As of December 31, 2023	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
U.S. Treasury securities	$	214,291	$	566	$	—	$	—	$	214,291	$	566
U.S. Government agency securities	4,998		2		—		—		4,998		2
Negotiable certificates of deposit	3,665		10		—		—		3,665		10
Total	$	222,954	$	578	$	—	$	—	$	222,954	$	578


	Less Than 12 Months				12 Months or Greater				Total
As of December 31, 2022	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
U.S. Treasury securities	$	178,568	$	1,056	$	61,377	$	1,267	$	239,945	$	2,323
U.S. Government agency securities	4,966		34		—		—		4,966		34
Corporate debt securities	2,228		21		13,846		265		16,074		286
Negotiable certificates of deposit	726		9		1,903		48		2,629		57
Total	$	186,488	$	1,120	$	77,126	$	1,580	$	263,614	$	2,700