Condensed Consolidating Financial Information - Condensed Consolidated Statement of Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jan. 28, 2017	Oct. 29, 2016	Jul. 30, 2016	Apr. 30, 2016	Jan. 30, 2016	Oct. 31, 2015	Aug. 01, 2015	May 02, 2015	Jan. 28, 2017	Jan. 30, 2016	Jan. 31, 2015
Condensed Statement of Comprehensive Income [Line Items]
Net income	$ 287.8	$ 14.8	$ 81.9	$ 146.8	$ 271.9	$ 15.0	$ 62.2	$ 118.8	$ 543.2	$ 467.9	$ 381.3
Other comprehensive (loss) income:
Foreign currency translation adjustments									(25.6)	(40.2)	(60.6)
Available-for-sale securities:
Unrealized gain (loss)									0.0	(0.4)	0.0
Cash flow hedges:
Unrealized gain (loss)									6.9	(11.8)	6.2
Reclassification adjustment for losses to net income									(0.6)	3.5	12.5
Pension plan:
Actuarial gain (loss)									(13.6)	10.9	(15.8)
Reclassification adjustment to net income for amortization of actuarial losses									1.2	2.7	1.6
Prior service costs									(0.4)	(0.5)	(0.7)
Reclassification adjustment to net income for amortization of net prior service credits									(1.5)	(1.7)	(1.3)
Total other comprehensive (loss) income									(33.6)	(37.5)	(58.1)
Total comprehensive income									509.6	430.4	323.2
Consolidation, Eliminations
Condensed Statement of Comprehensive Income [Line Items]
Net income									(1,116.6)	(1,045.4)	(1,529.0)
Other comprehensive (loss) income:
Foreign currency translation adjustments									25.6	40.2	56.5
Available-for-sale securities:
Unrealized gain (loss)									0.0	0.4	0.0
Cash flow hedges:
Unrealized gain (loss)									(6.9)	11.8	(6.2)
Reclassification adjustment for losses to net income									0.6	(3.5)	(12.5)
Pension plan:
Actuarial gain (loss)									13.6	(10.9)	15.8
Reclassification adjustment to net income for amortization of actuarial losses									(1.2)	(2.7)	(1.6)
Prior service costs									0.4	0.5	0.7
Reclassification adjustment to net income for amortization of net prior service credits									1.5	1.7	1.3
Total other comprehensive (loss) income									33.6	37.5	54.0
Total comprehensive income									(1,083.0)	(1,007.9)	(1,475.0)
Signet Jewelers Limited | Reportable Legal Entities
Condensed Statement of Comprehensive Income [Line Items]
Net income									543.2	467.9	381.3
Other comprehensive (loss) income:
Foreign currency translation adjustments									(25.6)	(40.2)	(60.6)
Available-for-sale securities:
Unrealized gain (loss)									0.0	(0.4)	0.0
Cash flow hedges:
Unrealized gain (loss)									6.9	(11.8)	6.2
Reclassification adjustment for losses to net income									(0.6)	3.5	12.5
Pension plan:
Actuarial gain (loss)									(13.6)	10.9	(15.8)
Reclassification adjustment to net income for amortization of actuarial losses									1.2	2.7	1.6
Prior service costs									(0.4)	(0.5)	(0.7)
Reclassification adjustment to net income for amortization of net prior service credits									(1.5)	(1.7)	(1.3)
Total other comprehensive (loss) income									(33.6)	(37.5)	(58.1)
Total comprehensive income									509.6	430.4	323.2
Signet UK Finance plc | Reportable Legal Entities
Condensed Statement of Comprehensive Income [Line Items]
Net income									(0.8)	(0.9)	(0.6)
Other comprehensive (loss) income:
Foreign currency translation adjustments									0.0	0.0	0.0
Available-for-sale securities:
Unrealized gain (loss)									0.0	0.0	0.0
Cash flow hedges:
Unrealized gain (loss)									0.0	0.0	0.0
Reclassification adjustment for losses to net income									0.0	0.0	0.0
Pension plan:
Actuarial gain (loss)									0.0	0.0	0.0
Reclassification adjustment to net income for amortization of actuarial losses									0.0	0.0	0.0
Prior service costs									0.0	0.0	0.0
Reclassification adjustment to net income for amortization of net prior service credits									0.0	0.0	0.0
Total other comprehensive (loss) income									0.0	0.0	0.0
Total comprehensive income									(0.8)	(0.9)	(0.6)
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Statement of Comprehensive Income [Line Items]
Net income									559.7	555.5	837.5
Other comprehensive (loss) income:
Foreign currency translation adjustments									(31.2)	(44.8)	(61.1)
Available-for-sale securities:
Unrealized gain (loss)									0.0	0.0	0.0
Cash flow hedges:
Unrealized gain (loss)									6.9	(11.8)	6.2
Reclassification adjustment for losses to net income									(0.6)	3.5	12.5
Pension plan:
Actuarial gain (loss)									(13.6)	10.9	(15.8)
Reclassification adjustment to net income for amortization of actuarial losses									1.2	2.7	1.6
Prior service costs									(0.4)	(0.5)	(0.7)
Reclassification adjustment to net income for amortization of net prior service credits									(1.5)	(1.7)	(1.3)
Total other comprehensive (loss) income									(39.2)	(41.7)	(58.6)
Total comprehensive income									520.5	513.8	778.9
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Statement of Comprehensive Income [Line Items]
Net income									557.7	490.8	692.1
Other comprehensive (loss) income:
Foreign currency translation adjustments									5.6	4.6	4.6
Available-for-sale securities:
Unrealized gain (loss)									0.0	(0.4)	0.0
Cash flow hedges:
Unrealized gain (loss)									0.0	0.0	0.0
Reclassification adjustment for losses to net income									0.0	0.0	0.0
Pension plan:
Actuarial gain (loss)									0.0	0.0	0.0
Reclassification adjustment to net income for amortization of actuarial losses									0.0	0.0	0.0
Prior service costs									0.0	0.0	0.0
Reclassification adjustment to net income for amortization of net prior service credits									0.0	0.0	0.0
Total other comprehensive (loss) income									5.6	4.2	4.6
Total comprehensive income									$ 563.3	$ 495.0	$ 696.7