Condensed consolidating financial information - Condensed consolidated statement of cash flows (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2016	May. 02, 2015
Cash flows from operating activities
Net cash provided by (used in) operating activities	$ 114.4	$ 67.0
Investing activities
Purchase of property, plant and equipment	(39.3)	(42.9)
Investment in subsidiaries	0.0	0.0
Purchase of available-for-sale securities	(0.8)	(1.4)
Proceeds from available-for-sale securities	1.2	3.5
Net cash used in investing activities	(38.9)	(40.8)
Financing activities
Dividends paid	(17.5)	(14.4)
Intra-entity dividends paid	0.0	0.0
Proceeds from issuance of common shares	0.3	0.1
Excess tax benefit from exercise of share awards	1.3	5.1
Proceeds from long-term debt	696.5	638.2
Proceeds from revolving credit facility	99.0	0.0
Repayments of revolving credit facility	55.0	0.0
Repurchase of common shares	(125.0)	(19.1)
Net settlement of equity based awards	(4.6)	(8.7)
Principal payments under capital lease obligations	(0.1)	(0.3)
Proceeds from short-term borrowings	6.0	(55.0)
Intra-entity activity, net	0.0	0.0
Net cash used in financing activities	(103.1)	(97.3)
Cash and cash equivalents at beginning of period	137.7	193.6
Decrease in cash and cash equivalents	(27.6)	(71.1)
Effect of exchange rate changes on cash and cash equivalents	2.9	0.1
Cash and cash equivalents at end of period	113.0	122.6
Consolidation, Eliminations
Cash flows from operating activities
Net cash provided by (used in) operating activities	(715.0)
Investing activities
Purchase of property, plant and equipment	0.0	0.0
Investment in subsidiaries	65.0
Purchase of available-for-sale securities	0.0	0.0
Proceeds from available-for-sale securities	0.0	0.0
Net cash used in investing activities	65.0	0.0
Financing activities
Dividends paid	0.0	0.0
Intra-entity dividends paid	715.0	0.0
Proceeds from issuance of common shares	(65.0)	0.0
Excess tax benefit from exercise of share awards	0.0	0.0
Proceeds from long-term debt	0.0	0.0
Proceeds from revolving credit facility	0.0	0.0
Repayments of revolving credit facility	0.0	0.0
Repurchase of common shares	0.0	0.0
Net settlement of equity based awards	0.0	0.0
Principal payments under capital lease obligations	0.0	0.0
Proceeds from short-term borrowings	0.0	0.0
Intra-entity activity, net	0.0
Net cash used in financing activities	650.0	0.0
Cash and cash equivalents at beginning of period	0.0	0.0
Decrease in cash and cash equivalents	0.0	0.0
Effect of exchange rate changes on cash and cash equivalents	0.0	0.0
Cash and cash equivalents at end of period	0.0	0.0
Signet Jewelers Limited | Reportable Legal Entities
Cash flows from operating activities
Net cash provided by (used in) operating activities	314.6	(3.4)
Investing activities
Purchase of property, plant and equipment	0.0	0.0
Investment in subsidiaries	(65.0)	0.0
Purchase of available-for-sale securities	0.0	0.0
Proceeds from available-for-sale securities	0.0	0.0
Net cash used in investing activities	(65.0)	0.0
Financing activities
Dividends paid	(17.5)	(14.4)
Intra-entity dividends paid	0.0	0.0
Proceeds from issuance of common shares	0.3	0.1
Excess tax benefit from exercise of share awards	0.0	0.0
Proceeds from long-term debt	0.0	0.0
Proceeds from revolving credit facility	0.0	0.0
Repayments of revolving credit facility	0.0	0.0
Repurchase of common shares	(125.0)	(19.1)
Net settlement of equity based awards	(4.6)	(8.7)
Principal payments under capital lease obligations	0.0	0.0
Proceeds from short-term borrowings	0.0	0.0
Intra-entity activity, net	(104.1)	44.3
Net cash used in financing activities	(250.9)	2.2
Cash and cash equivalents at beginning of period	1.9	2.1
Decrease in cash and cash equivalents	(1.3)	(1.2)
Effect of exchange rate changes on cash and cash equivalents	0.0	0.0
Cash and cash equivalents at end of period	0.6	0.9
Signet UK Finance plc | Reportable Legal Entities
Cash flows from operating activities
Net cash provided by (used in) operating activities	4.9	4.9
Investing activities
Purchase of property, plant and equipment	0.0	0.0
Investment in subsidiaries	0.0	0.0
Purchase of available-for-sale securities	0.0	0.0
Proceeds from available-for-sale securities	0.0	0.0
Net cash used in investing activities	0.0	0.0
Financing activities
Dividends paid	0.0	0.0
Intra-entity dividends paid	0.0	0.0
Proceeds from issuance of common shares	0.0	0.0
Excess tax benefit from exercise of share awards	0.0	0.0
Proceeds from long-term debt	0.0	0.0
Proceeds from revolving credit facility	0.0	0.0
Repayments of revolving credit facility	0.0	0.0
Repurchase of common shares	0.0	0.0
Net settlement of equity based awards	0.0	0.0
Principal payments under capital lease obligations	0.0	0.0
Proceeds from short-term borrowings	0.0	0.0
Intra-entity activity, net	(4.9)	(4.9)
Net cash used in financing activities	(4.9)	(4.9)
Cash and cash equivalents at beginning of period	0.1	0.1
Decrease in cash and cash equivalents	0.0	0.0
Effect of exchange rate changes on cash and cash equivalents	0.0	0.0
Cash and cash equivalents at end of period	0.1	0.1
Guarantor Subsidiaries | Reportable Legal Entities
Cash flows from operating activities
Net cash provided by (used in) operating activities	240.5	54.4
Investing activities
Purchase of property, plant and equipment	(39.3)	(42.9)
Purchase of available-for-sale securities	0.0	0.0
Proceeds from available-for-sale securities	0.0	0.0
Net cash used in investing activities	(39.3)	(42.9)
Financing activities
Dividends paid	0.0	0.0
Intra-entity dividends paid	(450.0)	0.0
Proceeds from issuance of common shares	65.0	0.0
Excess tax benefit from exercise of share awards	1.3	5.1
Proceeds from long-term debt	0.0	0.0
Proceeds from revolving credit facility	99.0	0.0
Repayments of revolving credit facility	(55.0)	0.0
Repurchase of common shares	0.0	0.0
Net settlement of equity based awards	0.0	0.0
Principal payments under capital lease obligations	(0.1)	(0.3)
Proceeds from short-term borrowings	6.0	(55.0)
Intra-entity activity, net	122.8	(12.5)
Net cash used in financing activities	(218.5)	(67.7)
Cash and cash equivalents at beginning of period	102.0	166.5
Decrease in cash and cash equivalents	(17.3)	(56.2)
Effect of exchange rate changes on cash and cash equivalents	2.9	0.1
Cash and cash equivalents at end of period	87.6	110.4
Non-Guarantor Subsidiaries | Reportable Legal Entities
Cash flows from operating activities
Net cash provided by (used in) operating activities	269.4	11.1
Investing activities
Purchase of available-for-sale securities	(0.8)	(1.4)
Proceeds from available-for-sale securities	1.2	3.5
Net cash used in investing activities	0.4	2.1
Financing activities
Dividends paid	0.0	0.0
Intra-entity dividends paid	(265.0)	0.0
Proceeds from long-term debt	696.5	638.2
Proceeds from revolving credit facility	0.0	0.0
Repayments of revolving credit facility	0.0	0.0
Repurchase of common shares	0.0	0.0
Net settlement of equity based awards	0.0	0.0
Principal payments under capital lease obligations	0.0	0.0
Proceeds from short-term borrowings	0.0	0.0
Intra-entity activity, net	(13.8)	(26.9)
Net cash used in financing activities	(278.8)	(26.9)
Cash and cash equivalents at beginning of period	33.7	24.9
Decrease in cash and cash equivalents	(9.0)	(13.7)
Cash and cash equivalents at end of period	24.7	11.2
Term Loan
Financing activities
Repayments of long-term debt	(7.5)	(5.0)
Term Loan | Consolidation, Eliminations
Financing activities
Repayments of long-term debt	0.0	0.0
Term Loan | Signet Jewelers Limited | Reportable Legal Entities
Financing activities
Repayments of long-term debt	0.0	0.0
Term Loan | Signet UK Finance plc | Reportable Legal Entities
Financing activities
Repayments of long-term debt	0.0	0.0
Term Loan | Guarantor Subsidiaries | Reportable Legal Entities
Financing activities
Repayments of long-term debt	(7.5)	(5.0)
Term Loan | Non-Guarantor Subsidiaries | Reportable Legal Entities
Financing activities
Repayments of long-term debt	0.0
Securitization facility
Financing activities
Repayments of long-term debt	(696.5)	(638.2)
Securitization facility | Consolidation, Eliminations
Financing activities
Repayments of long-term debt	0.0	0.0
Securitization facility | Signet Jewelers Limited | Reportable Legal Entities
Financing activities
Repayments of long-term debt	0.0	0.0
Securitization facility | Signet UK Finance plc | Reportable Legal Entities
Financing activities
Repayments of long-term debt	0.0	0.0
Securitization facility | Guarantor Subsidiaries | Reportable Legal Entities
Financing activities
Repayments of long-term debt	0.0	0.0
Securitization facility | Non-Guarantor Subsidiaries | Reportable Legal Entities
Financing activities
Repayments of long-term debt	$ (696.5)	$ (638.2)