Accounts receivable, net - Allowance for Credit Losses (Details) - USD ($) $ in Millions	6 Months Ended
Jul. 29, 2017	Jul. 30, 2016	Jan. 28, 2017
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	$ (138.7)
Balance before reversal	(135.0)	$ (129.4)
Reversal of allowance on receivables held for sale	(20.7)	0.0
Ending receivable balance evaluated for impairment	1,792.5	1,745.0	$ 1,952.0
Sterling Jewelers customer in-house finance receivables, net	664.5	1,650.6	$ 1,858.0
Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	(138.7)	(130.0)
Charge-offs, net	103.9	89.5
Recoveries	17.8	18.3
Provision	(118.0)	(107.2)
Balance before reversal	(135.0)	(129.4)
Reversal of allowance on receivables held for sale	20.7	0.0
Ending balance	114.3	129.4
Ending receivable balance evaluated for impairment	736.9	1,745.0
Sterling Jewelers customer in-house finance receivables, net	$ 622.6	$ 1,615.6

Financing Receivable, Allowance for Credit Losses, Net of Reversal

No definition available.

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- Definition

Financing Receivable, Allowance for Credit Losses, Reversal

+ References

No definition available.

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- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(4))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

A valuation allowance for financing receivables that are expected to be uncollectible.

+ References

+ Details

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- Definition

Amount of recovery of financing receivables doubtful of collection that were previously charged off.

+ References

+ Details

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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.

+ Details

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- Definition

Amount of direct write-downs of financing receivables charged against the allowance.

+ References

+ Details

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- Definition

The balance of financing receivables that were collectively evaluated for impairment.

+ References

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- Definition

Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

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