Condensed consolidating financial information - Condensed consolidated balance sheet (Details) - USD ($) $ in Millions	Aug. 01, 2015	May. 02, 2015	Jan. 31, 2015	Aug. 02, 2014	May. 03, 2014	Feb. 01, 2014
Current assets:
Cash and cash equivalents	$ 159.8	$ 122.6	$ 193.6	$ 215.0	$ 249.1	$ 247.6
Accounts receivable, net	1,493.2		1,567.6	1,316.0
Intra-entity receivables, net	0.0		0.0	0.0
Other receivables	55.2		63.6	54.1
Other current assets	126.8		137.2	120.5
Deferred tax assets	4.3		4.5	2.3
Income taxes	3.0		1.8	15.5
Inventories	2,414.2		2,439.0	2,345.3
Total current assets	4,256.5		4,407.3	4,068.7
Non-current assets:
Property, plant and equipment, net of accumulated depreciation of $915.1, $852.1 and $831.7, respectively	685.1		665.9	627.8
Goodwill	517.6		519.2	551.9		26.8
Intangible assets, net	437.8		447.1	467.6
Investment in subsidiaries	0.0			0.0
Intra-entity receivables, net	0.0			0.0
Other assets	145.4		140.0	133.0
Deferred tax assets	129.0		111.1	84.4
Retirement benefit asset	40.4		37.0	61.3
Total assets	6,211.8		6,327.6	5,994.7
Debt, Current	82.0		97.5	31.2
Current liabilities:
Accounts payable	194.0		277.7	235.0
Intra-entity payables, net			0.0	0.0
Accrued expenses and other current liabilities	453.1		482.4	422.1
Deferred revenue	230.2		248.0	211.1
Deferred tax liabilities	172.4		145.8	218.9
Income taxes	5.8		86.9	55.4
Total current liabilities	1,137.5		1,338.3	1,173.7
Non-current liabilities:
Long-term debt	1,348.7		1,363.8	1,379.1
Intra-entity payables, net				0.0
Other liabilities	226.2		230.2	235.4
Deferred revenue	607.0		563.9	520.4
Deferred tax liabilities	20.2		21.0	2.2
Total liabilities	3,339.6		3,517.2	3,310.8
Shareholders’ equity:
Total shareholders’ equity	2,872.2		2,810.4	2,683.9
Total liabilities and shareholders’ equity	6,211.8		6,327.6	5,994.7
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	(139.9)		(183.4)	(50.9)
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	(139.9)		(183.4)	(50.9)
Non-current assets:
Property, plant and equipment, net of accumulated depreciation of $915.1, $852.1 and $831.7, respectively	0.0			0.0
Goodwill	0.0			0.0
Intangible assets, net	0.0		0.0	0.0
Investment in subsidiaries	(3,970.7)		(3,585.8)	(3,628.8)
Intra-entity receivables, net	(3,882.4)		(3,892.4)	(3,733.9)
Other assets	0.0			0.0
Deferred tax assets	0.0			0.0
Retirement benefit asset	0.0			0.0
Total assets	(7,993.0)		(7,661.6)	(7,413.6)
Debt, Current	0.0		0.0	0.0
Current liabilities:
Accounts payable	0.0		0.0	0.0
Intra-entity payables, net	(139.9)		(183.4)	(50.9)
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	(139.9)		(183.4)	(50.9)
Non-current liabilities:
Intra-entity payables, net	(3,882.4)		(3,892.4)	(3,733.9)
Other liabilities				0.0
Deferred revenue				0.0
Deferred tax liabilities			0.0	0.0
Total liabilities	(4,022.3)		(4,075.8)	(3,784.8)
Shareholders’ equity:
Total shareholders’ equity	(3,970.7)		(3,585.8)	(3,628.8)
Total liabilities and shareholders’ equity	(7,993.0)		(7,661.6)	(7,413.6)
Signet Jewelers Limited | Reportable Legal Entities
Current assets:
Cash and cash equivalents	0.2	0.9	2.1	1.4	1.7	1.4
Accounts receivable, net	0.0		0.0	0.0
Intra-entity receivables, net	10.0		121.6	50.9
Other receivables	0.0		0.0	0.0
Other current assets	0.1		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	10.3		123.8	52.4
Non-current assets:
Property, plant and equipment, net of accumulated depreciation of $915.1, $852.1 and $831.7, respectively	0.0			0.0
Goodwill	0.0			0.0
Intangible assets, net	0.0		0.0	0.0
Investment in subsidiaries	2,879.9		2,701.3	2,646.2
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	2,890.2		2,825.1	2,698.6
Debt, Current	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	18.0		14.7	14.7
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	18.0		14.7	14.7
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	18.0		14.7	14.7
Shareholders’ equity:
Total shareholders’ equity	2,872.2		2,810.4	2,683.9
Total liabilities and shareholders’ equity	2,890.2		2,825.1	2,698.6
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 $915.1, $852.1 and $831.7, 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	402.5		402.4	403.9
Other assets	5.5		5.8	6.1
Deferred tax assets	0.0		0.0	0.0
Retirement benefit asset	0.0		0.0	0.0
Total assets	408.8		409.0	410.7
Debt, Current	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	2.4		2.4	5.0
Deferred revenue	0.0		0.0	0.0
Deferred tax liabilities	0.0		0.0	0.0
Income taxes	(0.1)		(0.2)	0.0
Total current liabilities	2.3		2.2	5.0
Non-current liabilities:
Long-term debt	398.5		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	400.8		400.7	403.4
Shareholders’ equity:
Total shareholders’ equity	8.0		8.3	7.3
Total liabilities and shareholders’ equity	408.8		409.0	410.7
Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	143.0	110.4	166.5	191.1	226.7	237.0
Accounts receivable, net	1,490.4		1,566.2	1,306.9
Intra-entity receivables, net	0.0		0.0	0.0
Other receivables	45.1		53.9	52.3
Other current assets	120.7		130.9	115.2
Deferred tax assets	3.9		4.3	2.1
Income taxes	3.0		1.8	14.9
Inventories	2,318.9		2,376.6	2,287.0
Total current assets	4,125.0		4,300.2	3,969.5
Non-current assets:
Property, plant and equipment, net of accumulated depreciation of $915.1, $852.1 and $831.7, respectively	679.5		660.2	621.6
Goodwill	514.0		515.6	548.3
Intangible assets, net	437.8		447.1	467.6
Investment in subsidiaries	554.9		462.8	546.8
Intra-entity receivables, net	0.0			0.0
Other assets	113.2		105.3	100.4
Deferred tax assets	128.9		111.0	84.4
Retirement benefit asset	40.4		37.0	61.3
Total assets	6,593.7		6,639.2	6,399.9
Debt, Current	82.0		97.5	31.2
Current liabilities:
Accounts payable	187.5		273.4	234.7
Intra-entity payables, net	139.9		183.4	19.7
Accrued expenses and other current liabilities	422.2		456.7	392.4
Deferred revenue	230.2		248.0	211.1
Deferred tax liabilities	172.4		145.8	218.9
Income taxes	6.5		87.7	60.4
Total current liabilities	1,240.7		1,492.5	1,168.4
Non-current liabilities:
Long-term debt	350.2		365.3	380.7
Intra-entity payables, net	3,882.4		3,892.4	3,733.9
Other liabilities	218.7		222.0	226.9
Deferred revenue	607.0		563.9	520.4
Deferred tax liabilities	20.2		21.0	2.2
Total liabilities	6,319.2		6,557.1	6,032.5
Shareholders’ equity:
Total shareholders’ equity	274.5		82.1	367.4
Total liabilities and shareholders’ equity	6,593.7		6,639.2	6,399.9
Non-Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	16.5	$ 11.2	24.9	22.5	$ 20.7	$ 9.2
Accounts receivable, net	2.8		1.4	9.1
Intra-entity receivables, net	129.9		61.8	0.0
Other receivables	10.1		9.7	1.8
Other current assets	5.3		5.5	4.5
Deferred tax assets	0.4		0.2	0.2
Income taxes	0.0			0.6
Inventories	95.3		62.4	58.3
Total current assets	260.3		165.9	97.0
Non-current assets:
Property, plant and equipment, net of accumulated depreciation of $915.1, $852.1 and $831.7, respectively	5.6		5.7	6.2
Goodwill	3.6		3.6	3.6
Intangible assets, net	0.0		0.0	0.0
Investment in subsidiaries	535.9		421.7	435.8
Intra-entity receivables, net	3,479.9		3,490.0	3,330.0
Other assets	26.7		28.9	26.5
Deferred tax assets	0.1		0.1	0.0
Retirement benefit asset	0.0			0.0
Total assets	4,312.1		4,115.9	3,899.1
Debt, Current	0.0		0.0	0.0
Current liabilities:
Accounts payable	6.5		4.3	0.3
Intra-entity payables, net	0.0		0.0	31.2
Accrued expenses and other current liabilities	10.5		8.6	10.0
Deferred revenue	0.0		0.0	0.0
Deferred tax liabilities	0.0		0.0	0.0
Income taxes	(0.6)		(0.6)	(5.0)
Total current liabilities	16.4		12.3	36.5
Non-current liabilities:
Long-term debt	600.0		600.0	600.0
Intra-entity payables, net				0.0
Other liabilities	7.5		8.2	8.5
Deferred revenue				0.0
Deferred tax liabilities			0.0	0.0
Total liabilities	623.9		620.5	645.0
Shareholders’ equity:
Total shareholders’ equity	3,688.2		3,495.4	3,254.1
Total liabilities and shareholders’ equity	$ 4,312.1		$ 4,115.9	$ 3,899.1