Condensed consolidating financial information - Condensed consolidated balance sheet (Details) - USD ($) $ in Millions	Nov. 03, 2018	Feb. 03, 2018	Oct. 28, 2017	Jan. 28, 2017
Current assets:
Cash and cash equivalents	$ 130.7	$ 225.1	$ 113.4	$ 98.7
Accounts receivable, held for sale	4.8	0.0	0.0
Accounts receivable, net	9.3	692.5	640.1
Intra-entity receivables, net	0.0	0.0	0.0
Other receivables	58.3	87.2	80.3
Other current assets	159.9	158.2	145.0
Income taxes	0.0	2.6	17.3
Inventories	2,647.1	2,280.5	2,466.1
Total current assets	3,010.1	3,446.1	3,462.2
Non-current assets:
Property, plant and equipment, net	810.4	877.9	855.1
Goodwill	509.0	821.7	867.1	517.6
Intangible assets, net	340.2	481.5	410.4
Investment in subsidiaries	0.0		0.0
Intra-entity receivables, net	0.0		0.0
Other assets	168.6	171.2	169.1
Deferred tax assets	36.2	1.4	1.3
Retirement benefit asset	33.0	39.8	35.5
Total assets	4,907.5	5,839.6	5,800.7
Current liabilities:
Loans and overdrafts	322.6	44.0	291.8
Accounts payable	339.6	237.0	324.9
Intra-entity payables, net		0.0	0.0
Accrued expenses and other current liabilities	431.3	448.0	430.5
Deferred revenue	253.1	288.6	270.3
Income taxes	19.1	19.6	0.0
Total current liabilities	1,365.7	1,037.2	1,317.5
Non-current liabilities:
Long-term debt	660.4	688.2	696.8
Other liabilities	233.2	239.6	244.4
Deferred revenue	671.7	668.9	646.1
Deferred tax liabilities	12.7	92.3	143.8
Total liabilities	2,943.7	2,726.2	3,048.6
Shareholders’ equity:
Total shareholders’ equity	1,349.0	2,499.8	2,139.0
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	4,907.5	5,839.6	5,800.7
Consolidation, Eliminations
Current assets:
Cash and cash equivalents	0.0	0.0	0.0	0.0
Accounts receivable, held for sale	0.0		0.0
Accounts receivable, net	0.0	0.0	0.0
Intra-entity receivables, net	(243.5)	(169.8)	(355.3)
Other receivables	0.0	0.0	0.0
Other current assets	0.0	0.0	0.0
Income taxes		0.0	0.0
Inventories	0.0	0.0	0.0
Total current assets	(243.5)	(169.8)	(355.3)
Non-current assets:
Property, plant and equipment, net	0.0		0.0
Goodwill	0.0		0.0
Intangible assets, net	0.0	0.0	0.0
Investment in subsidiaries	(2,071.2)	(4,919.8)	(3,874.4)
Intra-entity receivables, net	(2,993.0)	(3,259.0)	(3,235.0)
Other assets	0.0		0.0
Deferred tax assets	0.0		0.0
Retirement benefit asset	0.0		0.0
Total assets	(5,307.7)	(8,348.6)	(7,464.7)
Current liabilities:
Loans and overdrafts	0.0	0.0	0.0
Accounts payable	0.0	0.0	0.0
Intra-entity payables, net	(243.5)	(169.8)	(355.3)
Accrued expenses and other current liabilities	0.0	0.0	0.0
Deferred revenue	0.0	0.0	0.0
Income taxes	0.0	0.0	0.0
Total current liabilities	(243.5)	(169.8)	(355.3)
Non-current liabilities:
Long-term debt			0.0
Intra-entity payables, net	(2,993.0)	(3,259.0)	(3,235.0)
Other liabilities			0.0
Deferred revenue			0.0
Deferred tax liabilities		0.0	0.0
Total liabilities	(3,236.5)	(3,428.8)	(3,590.3)
Shareholders’ equity:
Total shareholders’ equity	(2,071.2)	(4,919.8)	(3,874.4)
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	(5,307.7)	(8,348.6)	(7,464.7)
Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	67.5	150.5	59.1	70.3
Accounts receivable, held for sale	4.8		0.0
Accounts receivable, net	6.9	692.5	638.7
Intra-entity receivables, net	0.0	0.0	0.0
Other receivables	33.4	62.0	55.6
Other current assets	158.1	154.4	140.0
Income taxes		2.6	17.3
Inventories	2,568.6	2,201.3	2,392.6
Total current assets	2,839.3	3,263.3	3,303.3
Non-current assets:
Property, plant and equipment, net	801.7	870.1	847.5
Goodwill	206.3	516.4	515.0
Intangible assets, net	266.4	410.9	410.4
Investment in subsidiaries	250.3	1,163.6	834.5
Intra-entity receivables, net	0.0		0.0
Other assets	150.9	140.1	136.9
Deferred tax assets	52.5	1.3	1.2
Retirement benefit asset	33.0	39.8	35.5
Total assets	4,600.4	6,405.5	6,084.3
Current liabilities:
Loans and overdrafts	323.3	44.7	292.5
Accounts payable	310.5	202.2	291.0
Intra-entity payables, net	149.1	158.5	355.3
Accrued expenses and other current liabilities	380.1	397.5	372.1
Deferred revenue	243.3	276.2	259.6
Income taxes		36.7	(24.3)
Total current liabilities	1,406.3	1,115.8	1,546.2
Non-current liabilities:
Long-term debt	264.6	293.0	301.8
Intra-entity payables, net	2,993.0	3,259.0	3,235.0
Other liabilities	228.0	233.0	238.8
Deferred revenue	671.7	668.9	646.1
Deferred tax liabilities	12.6	76.7	143.6
Total liabilities	5,576.2	5,646.4	6,111.5
Shareholders’ equity:
Total shareholders’ equity	(975.8)	759.1	(27.2)
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	4,600.4	6,405.5	6,084.3
Non-Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	62.6	72.8	53.8	26.6
Accounts receivable, held for sale	0.0		0.0
Accounts receivable, net	2.4		1.4
Intra-entity receivables, net	235.8	166.9	262.1
Other receivables	24.9	25.2	24.7
Other current assets	1.8	3.8	5.0
Income taxes			0.0
Inventories	78.5	79.2	73.5
Total current assets	406.0	347.9	420.5
Non-current assets:
Property, plant and equipment, net	8.7	7.8	7.6
Goodwill	302.7	305.3	352.1
Intangible assets, net	73.8	70.6	0.0
Investment in subsidiaries	(264.3)	606.0	346.2
Intra-entity receivables, net	2,593.0	2,859.0	2,835.0
Other assets	17.7	31.1	32.2
Deferred tax assets	(16.3)	0.1	0.1
Retirement benefit asset	0.0		0.0
Total assets	3,121.3	4,227.8	3,993.7
Current liabilities:
Loans and overdrafts	0.0	0.0	0.0
Accounts payable	29.1	34.8	33.9
Intra-entity payables, net	0.0	0.0	0.0
Accrued expenses and other current liabilities	16.6	20.9	23.7
Deferred revenue	9.8	12.4	10.7
Income taxes	19.1	(16.9)	24.5
Total current liabilities	74.6	51.2	92.8
Non-current liabilities:
Long-term debt			0.0
Other liabilities	5.2	6.6	5.6
Deferred revenue			0.0
Deferred tax liabilities	0.1	15.6	0.2
Total liabilities	79.9	73.4	98.6
Shareholders’ equity:
Total shareholders’ equity	3,041.4	4,154.4	3,895.1
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	3,121.3	4,227.8	3,993.7
Signet Jewelers Limited | Reportable Legal Entities
Current assets:
Cash and cash equivalents	0.5	1.7	0.4	1.7
Accounts receivable, held for sale	0.0		0.0
Accounts receivable, net	0.0	0.0	0.0
Intra-entity receivables, net			85.6
Other receivables	0.0	0.0	0.0
Other current assets		0.0	0.0
Income taxes		0.0	0.0
Inventories	0.0	0.0	0.0
Total current assets	0.5	1.7	86.0
Non-current assets:
Property, plant and equipment, net	0.0		0.0
Goodwill	0.0		0.0
Intangible assets, net	0.0	0.0	0.0
Investment in subsidiaries	2,085.2	3,150.2	2,693.7
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	2,085.7	3,151.9	2,779.7
Current liabilities:
Loans and overdrafts	0.0	0.0	0.0
Accounts payable	0.0	0.0	0.0
Intra-entity payables, net	94.4	11.3	0.0
Accrued expenses and other current liabilities	27.5	27.2	27.6
Deferred revenue	0.0	0.0	0.0
Income taxes	0.0	0.0	0.0
Total current liabilities	121.9	38.5	27.6
Non-current liabilities:
Long-term debt			0.0
Other liabilities			0.0
Deferred revenue			0.0
Deferred tax liabilities		0.0	0.0
Total liabilities	121.9	38.5	27.6
Shareholders’ equity:
Total shareholders’ equity	1,349.0	2,499.8	2,139.0
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	2,085.7	3,151.9	2,779.7
Signet UK Finance plc | Reportable Legal Entities
Current assets:
Cash and cash equivalents	0.1	0.1	0.1	$ 0.1
Accounts receivable, held for sale	0.0		0.0
Accounts receivable, net	0.0	0.0	0.0
Intra-entity receivables, net	7.7	2.9	7.6
Other receivables	0.0	0.0	0.0
Other current assets		0.0	0.0
Income taxes		0.0	0.0
Inventories	0.0	0.0	0.0
Total current assets	7.8	3.0	7.7
Non-current assets:
Property, plant and equipment, net	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	400.0	400.0	400.0
Other assets		0.0	0.0
Deferred tax assets	0.0	0.0	0.0
Retirement benefit asset	0.0	0.0	0.0
Total assets	407.8	403.0	407.7
Current liabilities:
Loans and overdrafts	(0.7)	(0.7)	(0.7)
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	7.1
Deferred revenue	0.0	0.0	0.0
Income taxes		(0.2)	(0.2)
Total current liabilities	6.4	1.5	6.2
Non-current liabilities:
Long-term debt	395.8	395.2	395.0
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	402.2	396.7	401.2
Shareholders’ equity:
Total shareholders’ equity	5.6	6.3	6.5
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	407.8	403.0	407.7
Series A Redeemable Convertible Preferred Stock
Non-current liabilities:
Series A redeemable convertible preferred shares	614.8	613.6	613.1
Series A Redeemable Convertible Preferred Stock | Consolidation, Eliminations
Non-current liabilities:
Series A redeemable convertible preferred shares	0.0	0.0	0.0
Series A Redeemable Convertible Preferred Stock | Guarantor Subsidiaries | Reportable Legal Entities
Non-current liabilities:
Series A redeemable convertible preferred shares	0.0	0.0	0.0
Series A Redeemable Convertible Preferred Stock | Non-Guarantor Subsidiaries | Reportable Legal Entities
Non-current liabilities:
Series A redeemable convertible preferred shares	0.0	0.0	0.0
Series A Redeemable Convertible Preferred Stock | Signet Jewelers Limited | Reportable Legal Entities
Non-current liabilities:
Series A redeemable convertible preferred shares	614.8	613.6	613.1
Series A Redeemable Convertible Preferred Stock | Signet UK Finance plc | Reportable Legal Entities
Non-current liabilities:
Series A redeemable convertible preferred shares	$ 0.0	$ 0.0	$ 0.0