Goodwill and intangibles - Summary of Goodwill (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
May 02, 2015	Jan. 31, 2015	May 03, 2014
Goodwill [Roll Forward]
Beginning Balance	$ 519.2us-gaap_Goodwill	$ 26.8us-gaap_Goodwill	$ 26.8us-gaap_Goodwill
Acquisitions		499.4us-gaap_GoodwillAcquiredDuringPeriod
Impact of foreign exchange	1.5us-gaap_GoodwillTranslationAdjustments	(7.0)us-gaap_GoodwillTranslationAdjustments
Ending Balance	520.7us-gaap_Goodwill	519.2us-gaap_Goodwill	26.8us-gaap_Goodwill
Sterling Jewelers
Goodwill [Roll Forward]
Beginning Balance	23.2	23.2
Acquisitions		0
Impact of foreign exchange	0	0
Ending Balance	23.2	23.2
Zale Jewelry
Goodwill [Roll Forward]
Beginning Balance	492.4	0
Acquisitions		499.4
Impact of foreign exchange	1.5	(7.0)
Ending Balance	493.9	492.4
Piercing Pagoda
Goodwill [Roll Forward]
Beginning Balance	0	0
Acquisitions		0
Impact of foreign exchange	0	0
Ending Balance	0	0
UK Jewelry
Goodwill [Roll Forward]
Beginning Balance	0	0
Acquisitions		0
Impact of foreign exchange	0	0
Ending Balance	0	0
Other
Goodwill [Roll Forward]
Beginning Balance	3.6	3.6
Acquisitions		0
Impact of foreign exchange	0	0
Ending Balance	$ 3.6	$ 3.6

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

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-Section 45

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Section 50

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Amount of increase (decrease) from foreign currency translation adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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