Investments (Tables)

12 Months Ended

Dec. 31, 2021

Schedule Of Investments [Abstract]

Summary of Fair Value of Available-for-Sale Investments by Type of Security

The fair value of available-for-sale investments by type of security was as follows:

	December 31, 2021
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Investments:
U.S treasury bills	$	189,406			$	(228	)	$	189,178
U.S agency securities		108,895				(138	)		108,757
Total investments with a maturity of one year or less		298,301		—		(366	)		297,935
U.S treasury bills		280,743				(535	)		280,208
U.S agency securities		99,998				(187	)		99,811
Total investments with a maturity of one to two years		380,741		—		(722	)		380,019
Total investments	$	679,042	$	—	$	(1,088	)	$	677,954

	December 31, 2020
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
Investments:
U.S treasury bills	$	29,997	$	21	$	—	$	30,018
U.S agency securities		20,996	5			—		21,001
Total investments with a maturity of one year or less		50,993		26		—		51,019
U.S treasury bills		3,008		—		—		3,008
U.S agency securities		176,350	38			—		176,388
Total investments with a maturity of one to two years		179,358		38		—		179,396
Total investments	$	230,351	$	64	$	—	$	230,415