Organization and principal accounting policies (Policies)	9 Months Ended
Oct. 29, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of preparation	Basis of preparation These condensed consolidated financial statements are prepared, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“US GAAP”) have been condensed or omitted from this report, as is permitted by such rules and regulations. In the opinion of management, the accompanying condensed consolidated financial statements reflect all adjustments, which are of a normal recurring nature, necessary for a fair presentation of the results for the interim periods. It is suggested that these condensed consolidated financial statements be read in conjunction with the consolidated financial statements and notes included in Signet’s Annual Report on Form 10-K for the fiscal year ended January 30, 2016 filed with the SEC on March 24, 2016.
Preferred shares	Preferred shares On October 5, 2016, the Company issued 625,000 shares of Series A Convertible Preference Shares (“preferred shares”) for an aggregate price of $625.0 million, or $1,000 per share (the “Stated Value”). The preferred shares were issued under an effective registration statement filed with the SEC. The accounting guidance under Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") Topic 480, "Distinguishing Liabilities from Equity," requires preferred securities that are redeemable for cash or other assets to be classified outside of permanent equity if redeemable at a fixed or determinable price on a fixed or determinable date, at the option of the holder, or upon the occurrence of an event that is not solely within the control of the issuer. The Company's preferred shares were classified as temporary equity and recorded in the condensed consolidated balance sheets at fair value upon issuance.
Use of estimates	Use of estimates The preparation of these condensed consolidated financial statements, in conformity with US GAAP and SEC regulations for interim reporting, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Estimates and assumptions are primarily made in relation to the valuation of accounts receivables, inventories, deferred revenue, derivatives, employee benefits, income taxes, contingencies, asset impairments, indefinite-lived intangible assets, as well as depreciation and amortization of long-lived assets.
Foreign currency transactions	Foreign currency translation The financial position and operating results of certain foreign operations, including the UK Jewelry division and the Canadian operations of the Zale Jewelry segment, are consolidated using the local currency as the functional currency. Assets and liabilities are translated at the rates of exchange on the balance sheet date, and revenues and expenses are translated at the monthly average rates of exchange during the period. Resulting translation gains or losses are included in the accompanying condensed consolidated statements of equity as a component of accumulated other comprehensive income (loss) (“AOCI”). Gains or losses resulting from foreign currency transactions are included within the condensed consolidated income statements, whereas translation adjustments and gains or losses related to intercompany loans of a long-term investment nature are recognized as a component of AOCI.
Reclassification	Reclassification The Company has reclassified the presentation of certain prior year amounts to conform to the current year presentation. During the fourth quarter of Fiscal 2016, the Company adopted FASB Accounting Standards Update ("ASU") No. 2015-17, "Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes." As a result, the Company adjusted the presentation of deferred taxes in the condensed consolidated balance sheet as of October 31, 2015 to reflect a reduction in current assets of $3.6 million, a reduction in non-current assets of $130.3 million, a reduction in current liabilities of $170.5 million and an increase in non-current liabilities of $36.6 million. See Note 2 for additional information regarding new accounting guidance adopted in Fiscal 2017.

Organization and principal accounting policies (Policies)

9 Months Ended

Oct. 29, 2016

Organization, Consolidation and Presentation of Financial Statements [Abstract]

These condensed consolidated financial statements are prepared, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“US GAAP”) have been condensed or omitted from this report, as is permitted by such rules and regulations. In the opinion of management, the accompanying condensed consolidated financial statements reflect all adjustments, which are of a normal recurring nature, necessary for a fair presentation of the results for the interim periods. It is suggested that these condensed consolidated financial statements be read in conjunction with the consolidated financial statements and notes included in Signet’s Annual Report on Form 10-K for the fiscal year ended January 30, 2016 filed with the SEC on March 24, 2016.

Preferred shares

On October 5, 2016, the Company issued 625,000 shares of Series A Convertible Preference Shares (“preferred shares”) for an aggregate price of $625.0 million, or $1,000 per share (the “Stated Value”). The preferred shares were issued under an effective registration statement filed with the SEC. The accounting guidance under Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") Topic 480, "Distinguishing Liabilities from Equity," requires preferred securities that are redeemable for cash or other assets to be classified outside of permanent equity if redeemable at a fixed or determinable price on a fixed or determinable date, at the option of the holder, or upon the occurrence of an event that is not solely within the control of the issuer. The Company's preferred shares were classified as temporary equity and recorded in the condensed consolidated balance sheets at fair value upon issuance.

Use of estimates

The preparation of these condensed consolidated financial statements, in conformity with US GAAP and SEC regulations for interim reporting, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Estimates and assumptions are primarily made in relation to the valuation of accounts receivables, inventories, deferred revenue, derivatives, employee benefits, income taxes, contingencies, asset impairments, indefinite-lived intangible assets, as well as depreciation and amortization of long-lived assets.

Foreign currency transactions

Foreign currency translation

The financial position and operating results of certain foreign operations, including the UK Jewelry division and the Canadian operations of the Zale Jewelry segment, are consolidated using the local currency as the functional currency. Assets and liabilities are translated at the rates of exchange on the balance sheet date, and revenues and expenses are translated at the monthly average rates of exchange during the period. Resulting translation gains or losses are included in the accompanying condensed consolidated statements of equity as a component of accumulated other comprehensive income (loss) (“AOCI”). Gains or losses resulting from foreign currency transactions are included within the condensed consolidated income statements, whereas translation adjustments and gains or losses related to intercompany loans of a long-term investment nature are recognized as a component of AOCI.

Reclassification

The Company has reclassified the presentation of certain prior year amounts to conform to the current year presentation. During the fourth quarter of Fiscal 2016, the Company adopted FASB Accounting Standards Update ("ASU") No. 2015-17, "Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes." As a result, the Company adjusted the presentation of deferred taxes in the condensed consolidated balance sheet as of October 31, 2015 to reflect a reduction in current assets of $3.6 million, a reduction in non-current assets of $130.3 million, a reduction in current liabilities of $170.5 million and an increase in non-current liabilities of $36.6 million. See Note 2 for additional information regarding new accounting guidance adopted in Fiscal 2017.