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Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
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Oct. 28, 2018 | Oct. 29, 2017 | Jan. 27, 2019 | Jan. 28, 2018 | Jan. 29, 2017
Accounting Policies [Abstract] |  |  |  |  |
Aggregate net investments under cost method of accounting |  |  | $ 16,700 | $ 38,100 |
Total equity method investments |  |  | 2,700 | 3,400 |
Impairment of investments | $ 30,000 | $ 4,300 | $ 30,000 | 4,250 | $ 0
Percent of realizable undiscounted cash flows used to determine useful life of acquired finite-lived intangible assets, minimum |  |  | 90.00% |  |
Advertising costs |  |  | $ 600 | 600 | 400
Recoveries from nonrecurring engineering services |  |  | $ 4,400 | $ 5,400 | $ 11,900

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- Definition Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 720 -SubTopic 35 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6420018&loc=d3e36677-107848 + Details
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