Financial Instruments - Fair Value of Assets Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Jan. 31, 2021	Feb. 02, 2020	Jan. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	$ 922,507	$ 932,260
Gross Unrealized Gains	9,255	7,263
Gross Unrealized Losses	(34)	(4)
Fair Value	981,712	965,874
Cash Equivalents	54,780	14,069
Marketable securities	916,388	936,518
Restricted cash	10,544	15,287	$ 15,823
Restricted Cash	10,544	15,287
Money market accounts \| Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	49,984	26,355
Cash Equivalents	39,440	11,068
Marketable securities	0	0
U.S. government treasury notes \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	339,253	323,751
Gross Unrealized Gains	3,241	2,146
Gross Unrealized Losses	(1)	0
Fair Value	342,493	325,897
Cash Equivalents	15,340	0
Marketable securities	327,153	325,897
Restricted Cash	0	0
U.S. government agencies \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	56,729	53,930
Gross Unrealized Gains	516	317
Gross Unrealized Losses	0	(3)
Fair Value	57,245	54,244
Cash Equivalents	0	0
Marketable securities	57,245	54,244
Restricted Cash	0	0
Corporate debt securities \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	425,115	452,318
Gross Unrealized Gains	4,176	3,954
Gross Unrealized Losses	(33)	(1)
Fair Value	429,258	456,271
Cash Equivalents	0	3,001
Marketable securities	429,258	453,270
Restricted Cash	0	0
Foreign government bonds \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	21,486	14,994
Gross Unrealized Gains	307	147
Gross Unrealized Losses	0	0
Fair Value	21,793	15,141
Cash Equivalents	0	0
Marketable securities	21,793	15,141
Restricted Cash	0	0
Asset-backed securities \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	79,924	87,267
Gross Unrealized Gains	1,015	699
Gross Unrealized Losses	0	0
Fair Value	80,939	87,966
Cash Equivalents	0	0
Marketable securities	80,939	87,966
Restricted Cash	$ 0	$ 0

Debt Securities, Available-for-sale, Cash Equivalents And Restricted Cash

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Debt Securities, Available-for-sale, Cash Equivalents And Restricted Cash, Accumulated Gross Unrealized Gain, Before Tax

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Debt Securities, Available-for-sale, Cash Equivalents And Restricted Cash, Accumulated Gross Unrealized Loss, Before Tax

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Debt Securities, Available-for-sale, Cash Equivalents And Restricted Cash, Amortized Cost

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as current.

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Amount of short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as noncurrent. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Amount of cash restricted as to withdrawal or usage, classified as noncurrent. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

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