Stock-based compensation - Restricted Stock Units (Details) - Restricted stock units - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
Apr. 30, 2022	May 01, 2021
Restricted stock units
Unrecognized compensation cost	$ 35,627
Stock compensation expense	$ 4,452	$ 4,835
Number of shares
Granted (in shares)	50	52

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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

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