Financial Instruments - (Tables)

6 Months Ended

Aug. 02, 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 at the end of fiscal 2020 and the second 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 Second 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	$	—	$	—	$	—	$	46,281	$	30,994	$	—	$	15,287
Level 2
U.S. government treasury notes	365,487		4,926		—		370,413		—		370,413		—
U.S. government agencies	46,120		598		(4)		46,714		—		46,714		—
Corporate debt securities	405,307		6,550		(2)		411,855		—		411,855		—
Foreign government bonds	18,770		430		—		19,200		—		19,200		—
Asset-backed securities	87,835		1,497		—		89,332		—		89,332		—
Total	$	923,519	$	14,001	$	(6)	$	983,795	$	30,994	$	937,514	$	15,287

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 Second Quarter of Fiscal 2021
	Amortized Cost		Fair Value
Due within one year	$	354,472	$	357,266
Due in one to five years	569,047		580,248
Total	$	923,519	$	937,514

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 second 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 Second 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 agencies	$	4,996	$	(4)	$	—	$	—	$	4,996	$	(4)
Corporate debt securities	1,309		(2)		—		—		1,309		(2)
Total	$	6,305	$	(6)	$	—	$	—	$	6,305	$	(6)