Organization and principal accounting policies	9 Months Ended
Oct. 28, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and principal accounting policies	Organization and principal accounting policies Signet Jewelers Limited (“Signet” or the “Company”), a holding company incorporated in Bermuda, is the world’s largest retailer of diamond jewelry. The Company operates through its 100% owned subsidiaries with sales primarily in the United States (“US”), United Kingdom (“UK”) and Canada. Signet manages its business as five reportable segments: the Sterling Jewelers division, the Zale division, which consists of the Zale Jewelry and Piercing Pagoda segments, the UK Jewelry division and Other. The “Other” reportable segment consists of all non-reportable segments, including subsidiaries involved in the purchasing and conversion of rough diamonds to polished stones and unallocated corporate administrative functions. See Note 5 for additional discussion of the Company’s segments. On September 12, 2017, the Company completed the acquisition of R2Net Inc., a Delaware corporation (“R2Net”). See Note 4 for additional information regarding the acquisition. In October 2017, the Company, through its subsidiary Sterling Jewelers Inc. (“Sterling”), completed the sale of the prime-only quality portion of Sterling’s in-house finance receivable portfolio to Comenity Bank (“Comenity”). See Note 3 for additional information regarding the transaction. Signet’s sales are seasonal, with the first quarter slightly exceeding 20% of annual sales, the second and third quarters each approximating 20% and the fourth quarter accounting for almost 40% of annual sales, with December being by far the most important month of the year. The “Holiday Season” consists of results for the months of November and December. As a result, approximately 45% to 55% of Signet’s annual operating income normally occurs in the fourth quarter, comprised of nearly all of the UK Jewelry and Zale divisions’ annual operating income and approximately 40% to 45% of the Sterling Jewelers division’s annual operating income. Basis of preparation The condensed consolidated financial statements of Signet 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 US generally accepted accounting principles (“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 28, 2017 filed with the SEC on March 16, 2017. 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 receivable, inventories, deferred revenue, derivatives, employee benefits, income taxes, contingencies, asset impairments, indefinite-lived intangible assets, depreciation and amortization of long-lived assets, as well as accounting for business combinations. Fiscal year The Company’s fiscal year ends on the Saturday nearest to January 31^st. Fiscal 2018 and Fiscal 2017 refer to the 53 week period ending February 3, 2018 and the 52 week period ending January 28, 2017, respectively. Within these condensed consolidated financial statements, the third quarter of the relevant fiscal years 2018 and 2017 refer to the 13 and 39 weeks ended October 28, 2017 and October 29, 2016, respectively. 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. See Note 9 for additional information regarding the Company’s foreign currency translation.

Organization and principal accounting policies

Signet Jewelers Limited (“Signet” or the “Company”), a holding company incorporated in Bermuda, is the world’s largest retailer of diamond jewelry. The Company operates through its 100% owned subsidiaries with sales primarily in the United States (“US”), United Kingdom (“UK”) and Canada. Signet manages its business as five reportable segments: the Sterling Jewelers division, the Zale division, which consists of the Zale Jewelry and Piercing Pagoda segments, the UK Jewelry division and Other. The “Other” reportable segment consists of all non-reportable segments, including subsidiaries involved in the purchasing and conversion of rough diamonds to polished stones and unallocated corporate administrative functions. See Note 5 for additional discussion of the Company’s segments.

On September 12, 2017, the Company completed the acquisition of R2Net Inc., a Delaware corporation (“R2Net”). See Note 4 for additional information regarding the acquisition.

In October 2017, the Company, through its subsidiary Sterling Jewelers Inc. (“Sterling”), completed the sale of the prime-only quality portion of Sterling’s in-house finance receivable portfolio to Comenity Bank (“Comenity”). See Note 3 for additional information regarding the transaction.

Signet’s sales are seasonal, with the first quarter slightly exceeding 20% of annual sales, the second and third quarters each approximating 20% and the fourth quarter accounting for almost 40% of annual sales, with December being by far the most important month of the year. The “Holiday Season” consists of results for the months of November and December. As a result, approximately 45% to 55% of Signet’s annual operating income normally occurs in the fourth quarter, comprised of nearly all of the UK Jewelry and Zale divisions’ annual operating income and approximately 40% to 45% of the Sterling Jewelers division’s annual operating income.

Basis of preparation

The condensed consolidated financial statements of Signet 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 US generally accepted accounting principles (“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 28, 2017 filed with the SEC on March 16, 2017.

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 receivable, inventories, deferred revenue, derivatives, employee benefits, income taxes, contingencies, asset impairments, indefinite-lived intangible assets, depreciation and amortization of long-lived assets, as well as accounting for business combinations.

Fiscal year

The Company’s fiscal year ends on the Saturday nearest to January 31^st. Fiscal 2018 and Fiscal 2017 refer to the 53 week period ending February 3, 2018 and the 52 week period ending January 28, 2017, respectively. Within these condensed consolidated financial statements, the third quarter of the relevant fiscal years 2018 and 2017 refer to the 13 and 39 weeks ended October 28, 2017 and October 29, 2016, respectively.

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.

See Note 9 for additional information regarding the Company’s foreign currency translation.