Restructuring Plan, Length

No definition available.

Name:	sig_RestructuringPlanLength
Namespace Prefix:	sig_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Restructuring Plan, Net Reduction in Net Selling Square Feet, Percent

+ References

No definition available.

+ Details

Name:	sig_RestructuringPlanNetReductioninNetSellingSquareFeetPercent
Namespace Prefix:	sig_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3367-108585

+ Details

Name:	us-gaap_PaymentsForRestructuring
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 5.P.3)
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140864-122747

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

+ Details

Name:	us-gaap_RestructuringCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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.

+ References

No definition available.

+ Details

Name:	us-gaap_RestructuringCostAndReserveLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_RestructuringPlanAxis=sig_SignetPathtoBrillanceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=sig_CostReductionActivitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Restructuring Plans - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Nov. 03, 2018	Oct. 28, 2017	Nov. 03, 2018	Oct. 28, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 80.2	$ 0.0
Signet Path to Brillance
Restructuring Cost and Reserve [Line Items]
Restructuring plan, length			3 years
Restructuring charges	$ 9.5	$ 0.0	$ 98.8	$ 0.0
Minimum \| Signet Path to Brillance
Restructuring Cost and Reserve [Line Items]
Restructuring charges			170.0
Cash payments			80.0
Maximum \| Signet Path to Brillance
Restructuring Cost and Reserve [Line Items]
Restructuring charges			190.0
Cash payments			$ 95.0
Net reduction in net selling square feet, percent			5.00%
Cost Reduction Activities \| Minimum \| Signet Path to Brillance
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 129.0
Cash payments			40.0
Cost Reduction Activities \| Maximum \| Signet Path to Brillance
Restructuring Cost and Reserve [Line Items]
Restructuring charges			134.0
Cash payments			$ 45.0