Cash, Cash Equivalents and Investments (Tables)

9 Months Ended

Sep. 30, 2020

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 September 30, 2020 and December 31, 2019 (in thousands):

	As of September 30, 2020
			Gross		Gross				Cash and
	Amortized		Unrealized		Unrealized				Cash		Short-Term		Long-Term
	Cost		Gains		Losses		Fair Value		Equivalents		Investments		Investments
Cash	$	91,499	$	—	$	—	$	91,499	$	91,499	$	—	$	—
Level 1:
Money market funds		31,298		—		—		31,298		31,298		—		—
Agency bonds		68,111		141		—		68,252		—		24,610		43,501
Treasury bills		57,284		3		—		57,287		5,499		51,785		—
Subtotal		156,693		144		—		156,837		36,797		76,395		43,501
Level 2:
State and municipal obligations		63,363		49		(14)		63,398		1,001		49,441		12,921
Certificates of deposit		1,900		—		—		1,900		—		1,400		500
Corporate bonds		222,817		389		(166)		223,040		2,908		156,178		63,731
U.S. Treasury repurchase agreements		43,800		—		—		43,800		43,800		—		—
Treasury inflation-protected securities		3,270		24		—		3,294		—		3,270		—
Commercial paper		44,356		—		—		44,356		—		44,356		—
Subtotal		379,506		462		(180)		379,788		47,709		254,645		77,152
Total	$	627,698	$	606	$	(180)	$	628,124	$	176,005	$	331,040	$	120,653

	As of December 31, 2019
			Gross		Gross				Cash and
	Amortized		Unrealized		Unrealized				Cash		Short-Term		Long-Term
	Cost		Gains		Losses		Fair Value		Equivalents		Investments		Investments
Cash	$	103,319	$	—	$	—	$	103,319	$	103,319	$	—	$	—
Level 1:
Money market funds		8,845		—		—		8,845		8,845		—		—
Agency bonds		32,869		14		(4)		32,879		—		15,131		17,738
Subtotal		41,714		14		(4)		41,724		8,845		15,131		17,738
Level 2:
State and municipal obligations		25,038		8		—		25,046		—		21,560		3,478
Certificates of deposit		1,400		—		—		1,400		—		1,400		—
Corporate bonds		135,175		71		(30)		135,216		886		113,241		21,048
U.S. Treasury repurchase agreements		57,200		—		—		57,200		57,200		—		—
Treasury inflation-protected securities		3,235		14		—		3,249		—		—		3,235
Commercial paper		29,202		—		—		29,202		2,000		27,202		—
Subtotal		251,250		93		(30)		251,313		60,086		163,403		27,761
Total	$	396,283	$	107	$	(34)	$	396,356	$	172,250	$	178,534	$	45,499