Share-Based Compensation - Additional Information about Awards Granted under Share Saving Plan (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
Feb. 03, 2018	Jan. 28, 2017	Jan. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash received from share options exercised	$ 0.3	$ 2.1	$ 5.0
Saving Share Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value per share of awards granted (usd per share)	$ 15.22	$ 22.82	$ 34.76
Total intrinsic value of options exercised	$ 0.1	$ 1.5	$ 6.4
Cash received from share options exercised	$ 0.3	$ 1.4	$ 4.0

Amount of cash inflow from exercise of stock options granted under share-based compensation arrangement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=SL79508275-113901

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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.

+ References

No definition available.

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- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ 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 (d)(2)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ 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 (d)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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