Investments - Schedule of Available-For-Sale Securities, Classified by Maturity Period (Details) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 26, 2020
Investments [Abstract]
Available-for-sale securities, Market Value - Within 1 year	$ 10,954
Available-for-sale securities, Adjusted Cost - Within 1 year	11,700
Available-for-sale securities, Market Value - After 1 year through 5 years	1,035
Available-for-sale securities, Adjusted Cost - After 1 year through 5 years	1,544
Available-for-sale securities, Market Value - Total investments	11,989	$ 10,700
Amortized Cost	$ 13,244	$ 8,715

Amortized cost 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
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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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