Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2022

Summary of Significant Accounting Policies [Abstract]

Adjusted Cost, Gross Unrealized Gains, Gross Unrealized Losses and Fair Value of Financial Assets

The following tables show the adjusted cost, gross unrealized gains, gross unrealized losses, and fair value of our securities by significant investment category as of March 31, 2022 and December 31, 2021.

	March 31, 2022
	Adjusted Cost		Unrealized Gains		Unrealized Losses			Fair Value		Cash and Cash Equivalents		Investments Available for Sale
Cash	$	31,449	$	—	$	—		$	31,449	$	31,449	$	—
Level 1:
Mutual funds		77,587		—		—			77,587		77,587		—
U.S. agency securities		24,163		—		(124	)		24,039		5,352		18,687
U.S. treasury securities		32,157		1		(97	)		32,061		22,020		10,041
		133,907		1		(221	)		133,687		104,959		28,728
Total	$	165,356	$	1	$	(221	)	$	165,136	$	136,408	$	28,728

	December 31, 2021
	Adjusted Cost		Unrealized Gains		Unrealized Losses			Fair Value		Cash and Cash Equivalents		Investments Available for Sale
Cash	$	35,428	$	—	$	—		$	35,428	$	35,428	$	—
Level 1:
Mutual funds		106,590		—		—			106,590		106,590		—
U.S. agency securities		16,658		—		(26	)		16,632		—		16,632
U.S. treasury securities		10,646		—		(24	)		10,622		—		10,622
		133,894		—		(50	)		133,844		106,590		27,254
Total	$	169,322	$	—	$	(50	)	$	169,272	$	142,018	$	27,254