Cash, Cash Equivalents and Investments (Tables)

3 Months Ended

Mar. 31, 2021

Cash and Cash Equivalents [Abstract]

Summary of Cash, Cash Equivalents and Held-to-Maturity Investments by Type

The following tables summarize our cash, cash equivalents, and held-to-maturity investments at March 31, 2021 and December 31, 2020 (in thousands):

	As of March 31, 2021
			Gross		Gross				Cash and
	Amortized		Unrealized		Unrealized				Cash		Short-Term		Long-Term
	Cost		Gains		Losses		Fair Value		Equivalents		Investments		Investments
Cash	$	137,003	$	—	$	—	$	137,003	$	137,003	$	—	$	—
Level 1:
Money market funds		16,819		—		—		16,819		16,819		—		—
Agency bonds		73,996		94		—		74,090		—		45,995		28,001
Treasury bills		104,184		13		—		104,197		—		104,184		—
Subtotal		194,999		107		—		195,106		16,819		150,179		28,001
Level 2:
State and municipal obligations		83,086		12		(30)		83,068		—		74,295		8,791
Certificates of deposit		500		—		—		500		—		500		—
Corporate bonds		186,406		140		(81)		186,465		1,002		143,712		41,692
Treasury inflation-protected securities		3,310		7		—		3,317		—		3,310		—
Commercial paper		68,961		—		—		68,961		—		68,961		—
Subtotal		342,263		159		(111)		342,311		1,002		290,778		50,483
Total	$	674,265	$	266	$	(111)	$	674,420	$	154,824	$	440,957	$	78,484

	As of December 31, 2020
			Gross		Gross				Cash and
	Amortized		Unrealized		Unrealized				Cash		Short-Term		Long-Term
	Cost		Gains		Losses		Fair Value		Equivalents		Investments		Investments
Cash	$	116,107	$	—	$	—	$	116,107	$	116,107	$	—	$	—
Level 1:
Money market funds		23,611		—		—		23,611		23,611		—		—
Agency bonds		63,794		122		—		63,916		—		23,794		40,000
Treasury Bills		96,384		6		—		96,390				96,384
Subtotal		183,789		128		—		183,917		23,611		120,178		40,000
Level 2:
State and municipal obligations		77,130		25		(28)		77,127		—		66,519		10,611
Certificates of deposit		500		—		—		500		—		500		—
Corporate bonds		212,825		232		(100)		212,957		2,525		170,205		40,095
U.S. Treasury repurchase agreements		13,200		—		—		13,200		13,200		—		—
Treasury inflation-protected securities		3,291		16		—		3,307		—		3,291
Commercial paper		45,974		—		—		45,974				45,974		—
Subtotal		352,920		273		(128)		353,065		15,725		286,489		50,706
Total	$	652,816	$	401	$	(128)	$	653,089	$	155,443	$	406,667	$	90,706