Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2021

Marketable Securities [Abstract]

Summary of Available-for-Sale Debt Securities

The following table summarizes the available-for-sale debt securities held at June 30, 2021 and December 31, 2020 and (in thousands):

Description	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
June 30, 2021
U.S. treasury securities	$	228,130	$	18	$	(5	)	$	228,143
Corporate securities		91,379		2		(15	)		91,366
Total	$	319,509	$	20	$	(20	)	$	319,509

Description	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
December 31, 2020
U.S. treasury securities	$	324,917	$	—	$	(53	)	$	324,864
Corporate securities		102,946		—		(81	)		102,865
Total	$	427,863	$	—	$	(134	)	$	427,729