Condensed consolidating financial information - Condensed consolidated statement of cash flows (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	May 02, 2015	May 03, 2014
Cash flows from operating activities:
Net cash provided by (used in) operating activities	$ 67.0	$ 73.5
Investing activities
Purchase of property, plant and equipment	(42.9)	(28.1)
Investment in subsidiaries	0
Purchase of available-for-sale securities	(1.4)	0
Proceeds from available-for-sale securities	3.5	0
Net cash used in investing activities	(40.8)	(28.1)
Financing activities
Dividends paid	(14.4)	(12.0)
Intra-entity dividends paid		0
Proceeds from issuance of common shares	0.1	1.0
Excess tax benefit from exercise of share awards	5.1	7.7
Proceeds from long-term debt	638.2
Repayment of long-term debt	(643.2)
Payment of debt issuance costs	0	(3.0)
Repurchase of common shares	(19.1)	(11.4)
Net settlement of equity based awards	(8.7)	(15.3)
Capital lease payments	(0.3)	0
Proceeds from (repayment of) short-term borrowings	(55.0)	(10.5)
Intra-entity activity, net	0	0
Net cash used in financing activities	(97.3)	(43.5)
Cash and cash equivalents at beginning of period	193.6	247.6
(Decrease) increase in cash and cash equivalents	(71.1)	1.9
Effect of exchange rate changes on cash and cash equivalents	0.1	(0.4)
Cash and cash equivalents at end of period	122.6	249.1
Consolidation, Eliminations
Investing activities
Purchase of property, plant and equipment	0	0
Purchase of available-for-sale securities	0
Proceeds from available-for-sale securities	0
Net cash used in investing activities	0	0
Financing activities
Dividends paid	0	0
Excess tax benefit from exercise of share awards	0	0
Proceeds from long-term debt	0
Repayment of long-term debt	0
Payment of debt issuance costs		0
Repurchase of common shares	0	0
Net settlement of equity based awards	0	0
Capital lease payments	0
Proceeds from (repayment of) short-term borrowings	0	0
Intra-entity activity, net	0
Net cash used in financing activities	0	0
Cash and cash equivalents at beginning of period	0	0
(Decrease) increase in cash and cash equivalents	0	0
Effect of exchange rate changes on cash and cash equivalents	0	0
Cash and cash equivalents at end of period	0	0
Signet Jewelers Limited | Reportable Legal Entities
Cash flows from operating activities:
Net cash provided by (used in) operating activities	(3.4)	(0.5)
Investing activities
Purchase of property, plant and equipment	0	0
Investment in subsidiaries	0
Purchase of available-for-sale securities	0
Proceeds from available-for-sale securities	0
Net cash used in investing activities	0	0
Financing activities
Dividends paid	(14.4)	(12.0)
Intra-entity dividends paid		0
Proceeds from issuance of common shares	0.1	1.0
Excess tax benefit from exercise of share awards	0	0
Proceeds from long-term debt	0
Repayment of long-term debt	0
Payment of debt issuance costs		0
Repurchase of common shares	(19.1)	(11.4)
Net settlement of equity based awards	(8.7)	(15.3)
Capital lease payments	0
Proceeds from (repayment of) short-term borrowings	0	0
Intra-entity activity, net	44.3	38.5
Net cash used in financing activities	2.2	0.8
Cash and cash equivalents at beginning of period	2.1	1.4
(Decrease) increase in cash and cash equivalents	(1.2)	0.3
Effect of exchange rate changes on cash and cash equivalents	0	0
Cash and cash equivalents at end of period	0.9	1.7
Signet UK Finance plc | Reportable Legal Entities
Cash flows from operating activities:
Net cash provided by (used in) operating activities	4.9	0
Investing activities
Purchase of property, plant and equipment	0	0
Investment in subsidiaries	0
Purchase of available-for-sale securities	0
Proceeds from available-for-sale securities	0
Net cash used in investing activities	0	0
Financing activities
Dividends paid	0	0
Intra-entity dividends paid		0
Proceeds from issuance of common shares		0
Excess tax benefit from exercise of share awards	0	0
Repayment of long-term debt	0
Payment of debt issuance costs		0
Repurchase of common shares	0	0
Net settlement of equity based awards	0	0
Capital lease payments	0
Proceeds from (repayment of) short-term borrowings	0	0
Intra-entity activity, net	(4.9)	0
Net cash used in financing activities	(4.9)	0
Cash and cash equivalents at beginning of period	0.1	0
(Decrease) increase in cash and cash equivalents	0	0
Effect of exchange rate changes on cash and cash equivalents	0	0
Cash and cash equivalents at end of period	0.1	0
Guarantor Subsidiaries | Reportable Legal Entities
Cash flows from operating activities:
Net cash provided by (used in) operating activities	54.4	62.4
Investing activities
Purchase of property, plant and equipment	(42.9)	(27.8)
Purchase of available-for-sale securities	0
Proceeds from available-for-sale securities	0
Net cash used in investing activities	(42.9)	(27.8)
Financing activities
Dividends paid	0	0
Intra-entity dividends paid		1.1
Proceeds from issuance of common shares		0
Excess tax benefit from exercise of share awards	5.1	7.7
Repayment of long-term debt	(5.0)
Payment of debt issuance costs		(3.0)
Repurchase of common shares	0	0
Net settlement of equity based awards	0	0
Capital lease payments	(0.3)
Proceeds from (repayment of) short-term borrowings	(55.0)	(10.5)
Intra-entity activity, net	(12.5)	(42.4)
Net cash used in financing activities	(67.7)	(47.1)
Cash and cash equivalents at beginning of period	166.5	237.0
(Decrease) increase in cash and cash equivalents	(56.2)	(12.5)
Effect of exchange rate changes on cash and cash equivalents	0.1	2.2
Cash and cash equivalents at end of period	110.4	226.7
Non-Guarantor Subsidiaries | Reportable Legal Entities
Cash flows from operating activities:
Net cash provided by (used in) operating activities	11.1	11.6
Investing activities
Purchase of property, plant and equipment		(0.3)
Purchase of available-for-sale securities	(1.4)
Proceeds from available-for-sale securities	3.5
Net cash used in investing activities	2.1	(0.3)
Financing activities
Dividends paid	0	0
Intra-entity dividends paid		(1.1)
Excess tax benefit from exercise of share awards	0	0
Proceeds from long-term debt	638.2
Repayment of long-term debt	(638.2)
Payment of debt issuance costs		0
Repurchase of common shares	0	0
Net settlement of equity based awards	0	0
Capital lease payments	0
Proceeds from (repayment of) short-term borrowings	0	0
Intra-entity activity, net	(26.9)	3.9
Net cash used in financing activities	(26.9)	2.8
Cash and cash equivalents at beginning of period	24.9	9.2
(Decrease) increase in cash and cash equivalents	(13.7)	14.1
Effect of exchange rate changes on cash and cash equivalents		(2.6)
Cash and cash equivalents at end of period	$ 11.2	$ 20.7