Investments - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Jan. 26, 2020	Jan. 27, 2019
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities	$ 10,700	$ 3,105
Available-for-sale, realized gain (loss)	(700)
Convertible Notes Payable
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities	$ 3,200
Interest rate	12.00%

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942338&loc=SL82898722-210454

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
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-Subparagraph (aa)
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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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-Publisher FASB
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-SubTopic 10
-Section S99
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Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
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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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