Condensed consolidating financial information - Condensed consolidated statement of comprehensive income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	May 02, 2015	May 03, 2014
Condensed Statement of Comprehensive Income [Line Items]
Net income	$ 118.8	$ 96.6
Other comprehensive income (loss):
Foreign currency translation adjustments	7.5	9.6
Available-for-sale securities:
Unrealized loss	(0.1)	0
Cash flow hedges:
Unrealized (loss) gain	(5.9)	0.3
Reclassification adjustment for losses to net income	0.5	4.7
Pension plan:
Reclassification adjustment to net income for amortization of actuarial loss	0.7	0.4
Reclassification adjustment to net income for amortization of prior service (credits) costs	(0.4)	(0.3)
Total other comprehensive income (loss)	2.3	14.7
Total comprehensive income	121.1	111.3
Consolidation, Eliminations
Condensed Statement of Comprehensive Income [Line Items]
Net income	(272.3)	(269.0)
Other comprehensive income (loss):
Foreign currency translation adjustments	(7.5)	0.5
Available-for-sale securities:
Unrealized loss	0.1
Cash flow hedges:
Unrealized (loss) gain	5.9
Reclassification adjustment for losses to net income	(0.5)
Pension plan:
Reclassification adjustment to net income for amortization of actuarial loss	(0.7)
Reclassification adjustment to net income for amortization of prior service (credits) costs	0.4
Total other comprehensive income (loss)	(2.3)	0.5
Total comprehensive income	(274.6)	(268.5)
Signet Jewelers Limited | Reportable Legal Entities
Condensed Statement of Comprehensive Income [Line Items]
Net income	118.8	96.6
Other comprehensive income (loss):
Foreign currency translation adjustments	7.5
Available-for-sale securities:
Unrealized loss	(0.1)
Cash flow hedges:
Unrealized (loss) gain	(5.9)
Reclassification adjustment for losses to net income	0.5
Pension plan:
Reclassification adjustment to net income for amortization of actuarial loss	0.7
Reclassification adjustment to net income for amortization of prior service (credits) costs	(0.4)
Total other comprehensive income (loss)	2.3	0
Total comprehensive income	121.1	96.6
Signet UK Finance plc | Reportable Legal Entities
Condensed Statement of Comprehensive Income [Line Items]
Net income	(0.2)	0
Other comprehensive income (loss):
Foreign currency translation adjustments	0	0
Available-for-sale securities:
Unrealized loss	0
Cash flow hedges:
Unrealized (loss) gain	0	0
Reclassification adjustment for losses to net income	0	0
Pension plan:
Reclassification adjustment to net income for amortization of actuarial loss	0	0
Reclassification adjustment to net income for amortization of prior service (credits) costs	0	0
Total other comprehensive income (loss)	0	0
Total comprehensive income	(0.2)	0
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Statement of Comprehensive Income [Line Items]
Net income	147.2	170.8
Other comprehensive income (loss):
Foreign currency translation adjustments	7.5	10.9
Available-for-sale securities:
Unrealized loss	0
Cash flow hedges:
Unrealized (loss) gain	(5.9)	0.3
Reclassification adjustment for losses to net income	0.5	4.7
Pension plan:
Reclassification adjustment to net income for amortization of actuarial loss	0.7	0.4
Reclassification adjustment to net income for amortization of prior service (credits) costs	(0.4)	(0.3)
Total other comprehensive income (loss)	2.4	16.0
Total comprehensive income	149.6	186.8
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Statement of Comprehensive Income [Line Items]
Net income	125.3	98.2
Other comprehensive income (loss):
Foreign currency translation adjustments		(1.8)
Available-for-sale securities:
Unrealized loss	(0.1)
Cash flow hedges:
Unrealized (loss) gain	0	0
Reclassification adjustment for losses to net income	0	0
Pension plan:
Reclassification adjustment to net income for amortization of actuarial loss	0	0
Reclassification adjustment to net income for amortization of prior service (credits) costs	0	0
Total other comprehensive income (loss)	(0.1)	(1.8)
Total comprehensive income	$ 125.2	$ 96.4