Cash, Cash Equivalents and Investments (Tables)

6 Months Ended

Jun. 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 June 30, 2020 and December 31, 2019 (in thousands):

	As of June 30, 2020
			Gross		Gross				Cash and
	Amortized		Unrealized		Unrealized				Cash		Short-Term		Long-Term
	Cost		Gains		Losses		Fair Value		Equivalents		Investments		Investments
Cash	$	141,191	$	—	$	—	$	141,191	$	141,191	$	—	$	—
Level 1:
Money market funds		92,773		—		—		92,773		92,773		—		—
Agency bonds		78,965		97		(6)		79,056		—		14,924		64,041
Treasury bills		32,093		1		—		32,094		7,999		24,094		—
Subtotal		203,831		98		(6)		203,923		100,772		39,018		64,041
Level 2:
State and municipal obligations		55,436		71		(14)		55,493		6,502		40,892		8,042
Certificates of deposit		1,900		—		—		1,900		—		1,400		500
Corporate bonds		196,247		515		(113)		196,649		9,102		130,117		57,028
U.S. Treasury repurchase agreements		55,500		—		—		55,500		55,500		—		—
Treasury inflation-protected securities		3,232		29		—		3,261		—		3,232		—
Commercial paper		29,616		—		—		29,616		6,197		23,419		—
Subtotal		341,931		615		(127)		342,419		77,301		199,060		65,570
Total	$	686,953	$	713	$	(133)	$	687,533	$	319,264	$	238,078	$	129,611

	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