Cash, Cash Equivalents and Investments

9 Months Ended

Sep. 30, 2020

Cash and Cash Equivalents [Abstract]

Cash, Cash Equivalents and Investments

3. Cash, Cash Equivalents and Investments

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

We adopted Topic 326 on January 1, 2020, and applied the credit loss guidance related to held-to-maturity securities prospectively. Because we do not have any history of losses for our held-to-maturity investments, our expected loss allowance methodology for held-to-maturity investments is developed using published or estimated credit default rates for similar investments and current and future economic and market conditions. At January 1 and September 30, 2020, our credit loss reserve for held-to-maturity investments was approximately $0.1 million and $0.2 million, respectively. During the three and nine months ended September 30, 2020, we increased the frequency of review for our investment portfolio in order to more closely monitor potential impacts of the novel coronavirus ("COVID-19”) pandemic.

	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