Condensed Consolidated Statement of Comprehensive Income (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Nov. 01, 2014	Nov. 02, 2013	Nov. 01, 2014	Nov. 02, 2013
Condensed Financial Statements, Captions [Line Items]
Net (loss) income	$ (1.3)	$ 33.6	$ 153.3	$ 192.8
Other comprehensive income (loss):
Foreign currency translation adjustments	(21.4)	10.5	(14.1)	3.5
Available-for-sale securities:
Unrealized loss			(0.2)
Cash flow hedges:
Unrealized gain (loss)	(1.5)	(1.5)	(1.3)	(18.3)
Reclassification adjustment for losses (gains) to net income	1.9	1.3	10.0	0.6
Pension plan:
Actuarial gain (loss)	0	0	0	0
Reclassification adjustment to net (loss) income for amortization of actuarial loss	0.4	0.4	1.2	1.3
Prior service (benefit) costs	0	0	0	0
Reclassification adjustment to net (loss) income for amortization of prior service credits	(0.3)	(0.2)	(1.0)	(0.8)
After-tax amount, Total other comprehensive (loss) income	(20.9)	10.5	(5.4)	(13.7)
Total comprehensive (loss) income	(22.2)	44.1	147.9	179.1
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net (loss) income	73.1	(84.6)	(312.0)	(518.5)
Other comprehensive income (loss):
Foreign currency translation adjustments	20.3	(9.6)	13.4	(3.2)
Available-for-sale securities:
Unrealized loss			0.2
Cash flow hedges:
Unrealized gain (loss)	1.5	1.5	1.3	18.3
Reclassification adjustment for losses (gains) to net income	(1.9)	(1.3)	(10.0)	(0.6)
Pension plan:
Actuarial gain (loss)	0	0	0	0
Reclassification adjustment to net (loss) income for amortization of actuarial loss	(0.4)	(0.4)	(1.2)	(1.3)
Prior service (benefit) costs	0	0	0	0
Reclassification adjustment to net (loss) income for amortization of prior service credits	0.3	0.2	1.0	0.8
After-tax amount, Total other comprehensive (loss) income	19.8	(9.6)	4.7	14.0
Total comprehensive (loss) income	92.9	(94.2)	(307.3)	(504.5)
Signet Jewelers Limited
Condensed Financial Statements, Captions [Line Items]
Net (loss) income	(1.3)	33.6	153.3	192.8
Other comprehensive income (loss):
Foreign currency translation adjustments	(21.4)	10.5	(14.1)	3.5
Available-for-sale securities:
Unrealized loss			(0.2)
Cash flow hedges:
Unrealized gain (loss)	(1.5)	(1.5)	(1.3)	(18.3)
Reclassification adjustment for losses (gains) to net income	1.9	1.3	10.0	0.6
Pension plan:
Actuarial gain (loss)	0	0	0	0
Reclassification adjustment to net (loss) income for amortization of actuarial loss	0.4	0.4	1.2	1.3
Prior service (benefit) costs	0	0	0	0
Reclassification adjustment to net (loss) income for amortization of prior service credits	(0.3)	(0.2)	(1.0)	(0.8)
After-tax amount, Total other comprehensive (loss) income	(20.9)	10.5	(5.4)	(13.7)
Total comprehensive (loss) income	(22.2)	44.1	147.9	179.1
Signet UK Finance plc
Condensed Financial Statements, Captions [Line Items]
Net (loss) income	(0.2)		(0.3)
Pension plan:
Actuarial gain (loss)	0	0	0	0
Prior service (benefit) costs	0	0	0	0
Total comprehensive (loss) income	(0.2)		(0.3)
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net (loss) income	(77.3)	47.5	147.7	321.5
Other comprehensive income (loss):
Foreign currency translation adjustments	(23.1)	12.0	(14.8)	4.0
Cash flow hedges:
Unrealized gain (loss)	(1.5)	(1.5)	(1.3)	(18.3)
Reclassification adjustment for losses (gains) to net income	1.9	1.3	10.0	0.6
Pension plan:
Actuarial gain (loss)	0	0	0	0
Reclassification adjustment to net (loss) income for amortization of actuarial loss	0.4	0.4	1.2	1.3
Prior service (benefit) costs	0	0	0	0
Reclassification adjustment to net (loss) income for amortization of prior service credits	(0.3)	(0.2)	(1.0)	(0.8)
After-tax amount, Total other comprehensive (loss) income	(22.6)	12.0	(5.9)	(13.2)
Total comprehensive (loss) income	(99.9)	59.5	141.8	308.3
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net (loss) income	4.4	37.1	164.6	197.0
Other comprehensive income (loss):
Foreign currency translation adjustments	2.8	(2.4)	1.4	(0.8)
Available-for-sale securities:
Unrealized loss			(0.2)
Pension plan:
Actuarial gain (loss)	0	0	0	0
Prior service (benefit) costs	0	0	0	0
After-tax amount, Total other comprehensive (loss) income	2.8	(2.4)	1.2	(0.8)
Total comprehensive (loss) income	$ 7.2	$ 34.7	$ 165.8	$ 196.2