Fair Value Measurements - Investment Impairments and Credit Loss Reserves (Details) - USD ($) $ in Thousands	6 Months Ended
Jul. 26, 2020	Jan. 27, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase in credit loss reserves on available-for-sale securities	$ 2,389
Credit loss reserve for available-for-sale and held-to-maturity debt securities	(2,900)
Impairment on non-marketable equity securities	$ 2,900
ASU 2016-13 \| Cumulative Effect, Period Of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Credit loss reserve on held-to-maturity securities		$ 400

Debt Securities, Available For Sale And Held To Maturity, Allowance For Credit Loss

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- Definition

Debt Securities, Non-Marketable Equity Securities, Change In Present Value, Expense (Reversal)

+ References

No definition available.

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- Definition

Amount of expense (reversal of expense) for expected credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), from change in present value of expected cash flows.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
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- Definition

Amount of allowance for credit loss for debt security measured at amortized cost (held-to-maturity).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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- Definition

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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No definition available.

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