Restructuring - Restructuring Reserve Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
Jan. 26, 2020	Jan. 27, 2019	Jan. 28, 2018
Restructuring Reserve [Roll Forward]
Beginning balance	$ 1,009	$ 4,749	$ 13
Charges	2,166	695	6,301
Cash payments	(2,937)	(4,435)	(1,565)
Ending balance	238	1,009	4,749
One-time employee termination benefits
Restructuring Reserve [Roll Forward]
Beginning balance	720	4,063	13
Charges	1,483	695	5,615
Cash payments	(2,026)	(4,038)	(1,565)
Ending balance	177	720	4,063
Contract commitments
Restructuring Reserve [Roll Forward]
Beginning balance	289	686	0
Charges	683	0	686
Cash payments	(911)	(397)	0
Ending balance	$ 61	$ 289	$ 686

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3367-108585

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- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 1
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- Definition

Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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