Financial Instruments - (Tables)

9 Months Ended

Nov. 01, 2020

Investments, Debt and Equity Securities [Abstract]

Cash Equivalents, Marketable Securities and Restricted Cash

The following tables summarize our cash equivalents, marketable securities and restricted cash by significant investment categories and their assigned levels within the valuation hierarchy at the end of fiscal 2020 and the third quarter of fiscal 2021 (in thousands):

	At the End of Fiscal 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value		Cash Equivalents		Marketable Securities		Restricted Cash
Level 1
Money market accounts	$	—	$	—	$	—	$	26,355	$	11,068	$	—	$	15,287
Level 2
U.S. government treasury notes	323,751		2,146		—		325,897		—		325,897		—
U.S. government agencies	53,930		317		(3)		54,244		—		54,244		—
Corporate debt securities	452,318		3,954		(1)		456,271		3,001		453,270		—
Foreign government bonds	14,994		147		—		15,141		—		15,141		—
Asset-backed securities	87,267		699		—		87,966		—		87,966		—
Total	$	932,260	$	7,263	$	(4)	$	965,874	$	14,069	$	936,518	$	15,287

	At the End of the Third Quarter of Fiscal 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value		Cash Equivalents		Marketable Securities		Restricted Cash
Level 1
Money market accounts	$	—	$	—	$	—	$	43,232	$	31,883	$	—	$	11,349
Level 2
U.S. government treasury notes	346,860		3,819		(5)		350,674		—		350,674		—
U.S. government agencies	56,723		543		(1)		57,265		—		57,265		—
Corporate debt securities	414,234		4,986		(37)		419,183		—		419,183		—
Foreign government bonds	20,497		348		(1)		20,844		—		20,844		—
Asset-backed securities	88,534		1,219		(1)		89,752		—		89,752		—
Total	$	926,848	$	10,915	$	(45)	$	980,950	$	31,883	$	937,718	$	11,349

Amortized Cost and Estimated Fair Value

The amortized cost and estimated fair value of our marketable securities are shown below by contractual maturity (in thousands):

	At the End of the Third Quarter of Fiscal 2021
	Amortized Cost		Fair Value
Due within one year	$	360,525	$	362,473
Due in one to five years	566,323		575,245
Total	$	926,848	$	937,718

Gross Unrealized Losses and Fair Values

The following table presents gross unrealized losses and fair values for those investments that were in a continuous unrealized loss position at the end of fiscal 2020 and the third quarter of fiscal 2021, aggregated by investment category (in thousands):

	At the End of Fiscal 2020
	Less than 12 months				Greater than 12 months				Total
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
U.S. government treasury notes	$	—	$	—	$	1,000	$	—	$	1,000	$	—
U.S. government agencies	4,998		(3)		—		—		4,998		(3)
Corporate debt securities	9,691		(1)		—		—		9,691		(1)
Total	$	14,689	$	(4)	$	1,000	$	—	$	15,689	$	(4)

	At the End of the Third Quarter of Fiscal 2021
	Less than 12 months				Greater than 12 months				Total
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
U.S. government treasury notes	$	58,412	$	(5)	$	—	$	—	$	58,412	$	(5)
U.S. government agencies	2,999		(1)		—		—		2,999		(1)
Corporate debt securities	29,930		(37)		—		—		29,930		(37)
Foreign government bonds	3,234		(1)		—		—		3,234		(1)
Asset-backed securities	6,786		(1)		—		—		6,786		(1)
Total	$	101,361	$	(45)	$	—	$	—	$	101,361	$	(45)