Conversion of Stock, Conversion Price

No definition available.

Name:	sig_ConversionofStockConversionPrice
Namespace Prefix:	sig_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Conversion of Stock, Conversion Ratio

+ References

No definition available.

+ Details

Name:	sig_ConversionofStockConversionRatio
Namespace Prefix:	sig_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Convertible Preferred Stock, Terms of Conversion, Common Stock Closing Price as Percentage of Conversion Price, Threshold

+ References

No definition available.

+ Details

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

- Definition

Convertible Preferred Stock, Terms of Conversion, Common Stock Closing Price as Percentage of Conversion Price, Trading Period

+ References

No definition available.

+ Details

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

- Definition

Preferred Dividends, Percentage of Average Quarterly Cash Dividends

+ References

No definition available.

+ Details

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

- Definition

Temporary Equity, Redemption Price, Percent

+ References

No definition available.

+ Details

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

- Definition

Aggregate number of common shares reserved for future issuance.

+ 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 210.5-02.29)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Adjustment to retained earnings for the increase in carrying amount of redeemable preferred stock that is classified as temporary equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 3.C)
-URI http://asc.fasb.org/extlink&oid=65877616&loc=d3e177168-122764

+ Details

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

- Definition

The cash outflow for cost incurred directly with the issuance of an equity security.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3291-108585

+ Details

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

- Definition

The percentage rate used to calculate dividend payments on preferred stock.

+ References

No definition available.

+ Details

Name:	us-gaap_PreferredStockDividendRatePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Per share or per unit amount of equity securities issued.

+ References

No definition available.

+ Details

Name:	us-gaap_SharesIssuedPricePerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

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

- Definition

The aggregate liquidation preference (or restrictions) of stock classified as temporary equity that has a preference in involuntary liquidation considerably in excess of the par or stated value of the shares. The liquidation preference is the difference between the preference in liquidation and the par or stated values of the share. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

+ 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 210.5-02.28(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_TemporaryEquityLiquidationPreference
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The number of securities classified as temporary equity that have been sold (or granted) to the entity's shareholders. Securities issued include securities outstanding and securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

+ 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(27)(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_TemporaryEquitySharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Value of new stock classified as temporary equity issued during the period.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_RedeemableConvertiblePreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Redeemable Preferred Shares - Narrative (Details) $ / shares in Units, $ in Millions			12 Months Ended
	Oct. 05, 2018	Oct. 05, 2016 USD ($) $ / shares shares	Jan. 28, 2017 USD ($) $ / shares shares
Temporary Equity [Line Items]
Dividends on redeemable convertible preferred shares			$ 11.9
Series A Redeemable Convertible Preferred Stock
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares issued \| shares		625,000
Preferred stock, purchase price		$ 625.0
Shares issued, price per share \| $ / shares		$ 1,000
Payments of stock issuance costs		$ 13.7
Dividends on redeemable convertible preferred shares			0.6
Liquidation preference			$ 636.3
Preferred stock, dividend rate, percentage			5.00%
Conversion ratio			10.6529
Conversion price \| $ / shares			$ 93.8712
Conversion of stock, shares issued \| shares			6,700,000
Percentage of cash equal to the stated value			101.00%
Maximum \| Series A Redeemable Convertible Preferred Stock
Temporary Equity [Line Items]
Preferred dividends, percentage of average quarterly cash dividends (not more than)			130.00%
Scenario, Forecast \| Series A Redeemable Convertible Preferred Stock
Temporary Equity [Line Items]
Percentage exceeding applicable conversion price	175.00%
Threshold period at which shares can be converted	20 days