Investments (Tables)

3 Months Ended

Mar. 31, 2021

Investments, Debt and Equity Securities [Abstract]

Summary of debt securities available-for-sale

The following table summarizes our cash equivalents and available-for-sale debt investments:

	March 31, 2021
									Fair Value Level
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses (1)		Total Fair Value		Level 1		Level 2
	(In thousands)
Cash equivalents
Certificate of deposits	$	901	$	—	$	—	$	901	$	901	$	—
Commercial paper	11,572		—		—		11,572		—		11,572
Corporate bonds	8,964		—		(5)		8,959		—		8,959
Money market funds	211,723		—		—		211,723		211,723		—
Municipal bonds	1,777		—		—		1,777		—		1,777
U.S. government bonds	250		—		—		250		250		—
Total cash equivalents	235,187		—		(5)		235,182		212,874		22,308
Short-term investments
Asset-backed securities	16,607		14		(7)		16,614		—		16,614
Certificate of deposits	10,178		—		—		10,178		10,178		—
Commercial paper	24,023		—		—		24,023		—		24,023
Corporate bonds	59,953		1		(27)		59,927		—		59,927
Municipal bonds	18,547		8		(3)		18,552		—		18,552
U.S. government agency bonds	1,585		—		—		1,585		—		1,585
U.S. government bonds	27,891		4		—		27,895		27,895		—
Variable rate demand notes	300		—		—		300		—		300
Total short-term investments	159,084		27		(37)		159,074		38,073		121,001
Total	$	394,271	$	27	$	(42)	$	394,256	$	250,947	$	143,309

	December 31, 2020
									Fair Value Level
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses (1)		Total Fair Value		Level 1		Level 2
	(In thousands)
Cash equivalents
Certificate of deposits	$	976	$	—	$	—	$	976	$	976	$	—
Commercial paper	5,293		—		—		5,293		—		5,293
Corporate bonds	1,744		—		—		1,744		—		1,744
Money market funds	138,290		—		—		138,290		138,290		—
Municipal bonds	400		—		—		400		—		400
Total cash equivalents	146,703		—		—		146,703		139,266		7,437
Short-term investments
Asset-backed securities	19,111		18		(9)		19,120		—		19,120
Certificate of deposits	5,046		—		—		5,046		5,046		—
Commercial paper	15,148		—		—		15,148		—		15,148
Corporate bonds	50,771		16		(12)		50,775		—		50,775
Municipal bonds	12,702		8		(2)		12,708		—		12,708
U.S. government agency bonds	8,415		3		—		8,418		—		8,418
U.S. government bonds	17,605		3		—		17,608		17,608		—
Variable rate demand notes	300		—		—		300		—		300
Total short-term investments	129,098		48		(23)		129,123		22,654		106,469
Total	$	275,801	$	48	$	(23)	$	275,826	$	161,920	$	113,906

(1)All unrealized losses have been in a continuous loss position for less than 12 months. We do not intend to sell the investments in an unrealized loss position, and it is not more likely than not that we will be required to sell these investments before recovery of their amortized cost bases.

The following table summarizes the contractual maturities of our cash equivalents and available-for-sale debt investments as of March 31, 2021:

	Amortized Cost		Fair Value
	(In thousands)
Within 1 year	$	379,754	$	379,731
After 1 year through 5 years	11,067		11,078
After 5 years through 10 years	3,450		3,447
Total	$	394,271	$	394,256