Stock-Based Awards - Narratives (Details) - USD ($) $ in Millions	3 Months Ended
Apr. 28, 2018	Jan. 27, 2018
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to stock options	$ 3.8
Total compensation cost not yet recognized, period for recognition	2 years 7 months 6 days
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to stock options	$ 11.5
Total compensation cost not yet recognized, period for recognition	2 years 9 months 18 days
Granted (in shares)	39,612
Shares outstanding	167,110	133,896
Performance RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to stock options	$ 31.9
Total compensation cost not yet recognized, period for recognition	2 years 6 months
Compensation expense	$ 13.4
RSUs outstanding (in shares)	158,841
Granted (in shares)	218,628
Shares outstanding	598,518	390,327
Target Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding	431,118
Supplemental Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	59,787
Shares outstanding	167,400

Potential Compensation Expense for Performance Based Shares If Performance Goals Are Met

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- Definition

Share-based compensation by share-based payment award, equity awards other than options, target amount of performance shares

+ References

No definition available.

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Unrecognized cost of unvested options awarded to employees as compensation.

+ References

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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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

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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