Cash, Cash Equivalents and Investments (Tables)

3 Months Ended

Mar. 31, 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 March 31, 2020 and December 31, 2019 (in thousands):

	As of March 31, 2020
			Gross		Gross				Cash and
	Amortized		Unrealized		Unrealized				Cash		Short-Term		Long-Term
	Cost		Gains		Losses		Fair Value		Equivalents		Investments		Investments
Cash	$	73,560	$	—	$	—	$	73,560	$	73,560	$	—	$	—
Level 1:
Money market funds		3,536		—		—		3,536		3,536		—		—
Agency bonds		40,340		91		(2)		40,429		2,000		12,738		25,602
Treasury bills		17,983		15				17,998		10,995		6,988
Subtotal		61,859		106		(2)		61,963		16,531		19,726		25,602
Level 2:
State and municipal obligations		32,185		34		(27)		32,192		1,991		29,687		507
Certificates of deposit		1,900		—		—		1,900		—		1,400		500
Corporate bonds		145,022		79		(959)		144,142		4,987		119,654		20,381
U.S. Treasury repurchase agreements		49,400		—		—		49,400		49,400		—		—
Treasury inflation-protected securities		3,247		—		(47)		3,200		—		—		3,247
Commercial paper		28,364		—		—		28,364		10,072		18,292		—
Subtotal		260,118		113		(1,033)		259,198		66,450		169,033		24,635
Total	$	395,537	$	219	$	(1,035)	$	394,721	$	156,541	$	188,759	$	50,237

	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