Condensed consolidating financial information - Condensed consolidated balance sheet (Details) - USD ($) $ in Millions	Oct. 31, 2015	Aug. 01, 2015	Jan. 31, 2015	Nov. 01, 2014	Aug. 02, 2014	Feb. 01, 2014
Current assets:
Cash and cash equivalents	$ 77.2	$ 159.8	$ 193.6	$ 87.6	$ 215.0	$ 247.6
Accounts receivable, net	1,451.5		1,567.6	1,292.1
Intra-entity receivables, net	0.0		0.0	0.0
Other receivables	55.4		63.6	56.7
Other current assets	143.2		137.2	133.7
Deferred tax assets	3.6		4.5	1.6
Income taxes	24.6		1.8	21.6
Inventories	2,727.0		2,439.0	2,674.6
Total current assets	4,482.5		4,407.3	4,267.9
Non-current assets:
Property, plant and equipment, net of accumulated depreciation of $939.7, $852.1 and $839.0, respectively	718.0		665.9	658.8
Goodwill	517.6		519.2	524.3		26.8
Intangible assets, net	434.3		447.1	461.3
Investment in subsidiaries	0.0			0.0
Intra-entity receivables, net	0.0			0.0
Other assets	144.5		140.0	133.5
Deferred tax assets	132.1		111.1	72.8
Retirement benefit asset	40.7		37.0	59.9
Total assets	6,469.7		6,327.6	6,178.5
Loans and overdrafts	249.8		97.5	221.8
Current liabilities:
Accounts payable	371.4		277.7	396.2
Intra-entity payables, net			0.0	0.0
Accrued expenses and other current liabilities	408.0		482.4	422.7
Deferred revenue	241.4		248.0	221.6
Deferred tax liabilities	170.5		145.8	151.2
Income taxes	0.7		86.9	3.6
Total current liabilities	1,441.8		1,338.3	1,417.1
Non-current liabilities:
Long-term debt	1,338.7		1,363.8	1,371.3
Intra-entity payables, net				0.0
Other liabilities	226.6		230.2	227.2
Deferred revenue	597.5		563.9	518.8
Deferred tax liabilities	20.1		21.0	1.8
Total liabilities	3,624.7		3,517.2	3,536.2
Shareholders’ equity:
Total shareholders’ equity	2,845.0		2,810.4	2,642.3
Total liabilities and shareholders’ equity	6,469.7		6,327.6	6,178.5
Consolidation, Eliminations
Current assets:
Cash and cash equivalents	0.0	0.0	0.0	0.0	0.0	0.0
Accounts receivable, net	0.0		0.0	0.0
Intra-entity receivables, net	(244.0)		(183.4)	(159.3)
Other receivables	0.0		0.0	0.0
Other current assets	0.0		0.0	0.0
Deferred tax assets	0.0		0.0	0.0
Income taxes	0.0		0.0	0.0
Inventories	0.0		0.0	0.0
Total current assets	(244.0)		(183.4)	(159.3)
Non-current assets:
Property, plant and equipment, net of accumulated depreciation of $939.7, $852.1 and $839.0, respectively	0.0			0.0
Goodwill	0.0			0.0
Intangible assets, net	0.0		0.0	0.0
Investment in subsidiaries	(3,867.1)		(3,585.8)	(3,459.5)
Intra-entity receivables, net	(3,882.2)		(3,892.4)	(3,733.5)
Other assets	0.0			0.0
Deferred tax assets	0.0			0.0
Retirement benefit asset	0.0			0.0
Total assets	(7,993.3)		(7,661.6)	(7,352.3)
Loans and overdrafts	0.0		0.0	0.0
Current liabilities:
Accounts payable	0.0		0.0	0.0
Intra-entity payables, net	(244.0)		(183.4)	(159.3)
Accrued expenses and other current liabilities	0.0		0.0	0.0
Deferred revenue	0.0		0.0	0.0
Deferred tax liabilities	0.0		0.0	0.0
Income taxes	0.0		0.0	0.0
Total current liabilities	(244.0)		(183.4)	(159.3)
Non-current liabilities:
Intra-entity payables, net	(3,882.2)		(3,892.4)	(3,733.5)
Other liabilities				0.0
Deferred revenue				0.0
Deferred tax liabilities			0.0	0.0
Total liabilities	(4,126.2)		(4,075.8)	(3,892.8)
Shareholders’ equity:
Total shareholders’ equity	(3,867.1)		(3,585.8)	(3,459.5)
Total liabilities and shareholders’ equity	(7,993.3)		(7,661.6)	(7,352.3)
Signet Jewelers Limited | Reportable Legal Entities
Current assets:
Cash and cash equivalents	3.1	0.2	2.1	2.9	1.4	1.4
Accounts receivable, net	0.0		0.0	0.0
Intra-entity receivables, net	61.9		121.6	129.9
Other receivables	0.0		0.0	0.0
Other current assets	0.2		0.1	0.1
Deferred tax assets	0.0		0.0	0.0
Income taxes	0.0		0.0	0.0
Inventories	0.0		0.0	0.0
Total current assets	65.2		123.8	132.9
Non-current assets:
Property, plant and equipment, net of accumulated depreciation of $939.7, $852.1 and $839.0, respectively	0.0			0.0
Goodwill	0.0			0.0
Intangible assets, net	0.0		0.0	0.0
Investment in subsidiaries	2,797.6		2,701.3	2,524.2
Intra-entity receivables, net	0.0			0.0
Other assets	0.0			0.0
Deferred tax assets	0.0			0.0
Retirement benefit asset	0.0			0.0
Total assets	2,862.8		2,825.1	2,657.1
Loans and overdrafts	0.0		0.0	0.0
Current liabilities:
Accounts payable	0.0		0.0	0.0
Intra-entity payables, net	0.0		0.0	0.0
Accrued expenses and other current liabilities	17.8		14.7	14.8
Deferred revenue	0.0		0.0	0.0
Deferred tax liabilities	0.0		0.0	0.0
Income taxes	0.0		0.0	0.0
Total current liabilities	17.8		14.7	14.8
Non-current liabilities:
Intra-entity payables, net				0.0
Other liabilities				0.0
Deferred revenue				0.0
Deferred tax liabilities			0.0	0.0
Total liabilities	17.8		14.7	14.8
Shareholders’ equity:
Total shareholders’ equity	2,845.0		2,810.4	2,642.3
Total liabilities and shareholders’ equity	2,862.8		2,825.1	2,657.1
Signet UK Finance plc | Reportable Legal Entities
Current assets:
Cash and cash equivalents	0.1	0.1	0.1	0.0	0.0	0.0
Accounts receivable, net	0.0		0.0	0.0
Intra-entity receivables, net	0.0		0.0	0.0
Other receivables	0.0		0.0	0.0
Other current assets	0.7		0.7	0.7
Deferred tax assets	0.0		0.0	0.0
Income taxes	0.0		0.0	0.0
Inventories	0.0		0.0	0.0
Total current assets	0.8		0.8	0.7
Non-current assets:
Property, plant and equipment, net of accumulated depreciation of $939.7, $852.1 and $839.0, respectively	0.0		0.0	0.0
Goodwill	0.0		0.0	0.0
Intangible assets, net	0.0		0.0	0.0
Investment in subsidiaries	0.0		0.0	0.0
Intra-entity receivables, net	407.2		402.4	408.5
Other assets	5.3		5.8	6.0
Deferred tax assets	0.0		0.0	0.0
Retirement benefit asset	0.0		0.0	0.0
Total assets	413.3		409.0	415.2
Loans and overdrafts	0.0		0.0	0.0
Current liabilities:
Accounts payable	0.0		0.0	0.0
Intra-entity payables, net	0.0		0.0	0.0
Accrued expenses and other current liabilities	7.1		2.4	8.4
Deferred revenue	0.0		0.0	0.0
Deferred tax liabilities	0.0		0.0	0.0
Income taxes	(0.2)		(0.2)	(0.1)
Total current liabilities	6.9		2.2	8.3
Non-current liabilities:
Long-term debt	398.6		398.5	398.4
Intra-entity payables, net			0.0	0.0
Other liabilities			0.0	0.0
Deferred revenue			0.0	0.0
Deferred tax liabilities			0.0	0.0
Total liabilities	405.5		400.7	406.7
Shareholders’ equity:
Total shareholders’ equity	7.8		8.3	8.5
Total liabilities and shareholders’ equity	413.3		409.0	415.2
Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	61.0	143.0	166.5	74.1	191.1	237.0
Accounts receivable, net	1,447.1		1,566.2	1,281.9
Intra-entity receivables, net	0.0		0.0	0.0
Other receivables	45.4		53.9	55.0
Other current assets	136.5		130.9	127.1
Deferred tax assets	3.0		4.3	1.4
Income taxes	24.6		1.8	21.0
Inventories	2,643.1		2,376.6	2,619.1
Total current assets	4,360.7		4,300.2	4,179.6
Non-current assets:
Property, plant and equipment, net of accumulated depreciation of $939.7, $852.1 and $839.0, respectively	712.5		660.2	652.8
Goodwill	514.0		515.6	520.7
Intangible assets, net	434.3		447.1	461.3
Investment in subsidiaries	532.4		462.8	484.0
Intra-entity receivables, net	0.0			0.0
Other assets	110.8		105.3	100.0
Deferred tax assets	132.0		111.0	72.7
Retirement benefit asset	40.7		37.0	59.9
Total assets	6,837.4		6,639.2	6,531.0
Loans and overdrafts	249.8		97.5	221.8
Current liabilities:
Accounts payable	367.4		273.4	396.0
Intra-entity payables, net	244.0		183.4	159.3
Accrued expenses and other current liabilities	372.8		456.7	389.5
Deferred revenue	241.4		248.0	221.6
Deferred tax liabilities	170.5		145.8	151.2
Income taxes	(14.9)		87.7	(3.8)
Total current liabilities	1,631.0		1,492.5	1,535.6
Non-current liabilities:
Long-term debt	340.1		365.3	372.9
Intra-entity payables, net	3,882.2		3,892.4	3,733.5
Other liabilities	219.5		222.0	219.1
Deferred revenue	597.5		563.9	518.8
Deferred tax liabilities	20.1		21.0	1.8
Total liabilities	6,690.4		6,557.1	6,381.7
Shareholders’ equity:
Total shareholders’ equity	147.0		82.1	149.3
Total liabilities and shareholders’ equity	6,837.4		6,639.2	6,531.0
Non-Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	13.0	$ 16.5	24.9	10.6	$ 22.5	$ 9.2
Accounts receivable, net	4.4		1.4	10.2
Intra-entity receivables, net	182.1		61.8	29.4
Other receivables	10.0		9.7	1.7
Other current assets	5.8		5.5	5.8
Deferred tax assets	0.6		0.2	0.2
Income taxes	0.0			0.6
Inventories	83.9		62.4	55.5
Total current assets	299.8		165.9	114.0
Non-current assets:
Property, plant and equipment, net of accumulated depreciation of $939.7, $852.1 and $839.0, respectively	5.5		5.7	6.0
Goodwill	3.6		3.6	3.6
Intangible assets, net	0.0		0.0	0.0
Investment in subsidiaries	537.1		421.7	451.3
Intra-entity receivables, net	3,475.0		3,490.0	3,325.0
Other assets	28.4		28.9	27.5
Deferred tax assets	0.1		0.1	0.1
Retirement benefit asset	0.0			0.0
Total assets	4,349.5		4,115.9	3,927.5
Loans and overdrafts	0.0		0.0	0.0
Current liabilities:
Accounts payable	4.0		4.3	0.2
Intra-entity payables, net	0.0		0.0	0.0
Accrued expenses and other current liabilities	10.3		8.6	10.0
Deferred revenue	0.0		0.0	0.0
Deferred tax liabilities	0.0		0.0	0.0
Income taxes	15.8		(0.6)	7.5
Total current liabilities	30.1		12.3	17.7
Non-current liabilities:
Long-term debt	600.0		600.0	600.0
Intra-entity payables, net				0.0
Other liabilities	7.1		8.2	8.1
Deferred revenue				0.0
Deferred tax liabilities			0.0	0.0
Total liabilities	637.2		620.5	625.8
Shareholders’ equity:
Total shareholders’ equity	3,712.3		3,495.4	3,301.7
Total liabilities and shareholders’ equity	$ 4,349.5		$ 4,115.9	$ 3,927.5