Condensed consolidating financial information - Condensed consolidated balance sheet (Details) - USD ($) $ in Millions	May 05, 2018	Feb. 03, 2018	Apr. 29, 2017	Jan. 28, 2017
Current assets:
Cash and cash equivalents	$ 153.9	$ 225.1	$ 99.7	$ 98.7
Accounts receivable, held for sale	484.6	0.0	0.0
Accounts receivable, net	6.8	692.5	1,726.3
Intra-entity receivables, net	0.0	0.0	0.0
Other receivables	83.6	87.2	88.6
Other current assets	153.2	158.2	159.0
Income taxes	55.2	2.6	1.8
Inventories	2,429.0	2,280.5	2,432.4
Total current assets	3,366.3	3,446.1	4,507.8
Non-current assets:
Property, plant and equipment, net	847.2	877.9	829.8
Goodwill	509.1	821.7	516.1	517.6
Intangible assets, net	343.2	481.5	411.9
Investment in subsidiaries	0.0		0.0
Intra-entity receivables, net	0.0		0.0
Other assets	167.0	171.2	165.1
Deferred tax assets	0.8	1.4	0.6
Retirement benefit asset	39.3	39.8	33.9
Total assets	5,272.9	5,839.6	6,465.2
Current liabilities:
Loans and overdrafts	72.3	44.0	131.5
Accounts payable	287.5	237.0	177.8
Intra-entity payables, net		0.0	0.0
Accrued expenses and other current liabilities	463.7	448.0	400.3
Deferred revenue	284.9	288.6	272.1
Income taxes	0.0	19.6	34.2
Total current liabilities	1,108.4	1,037.2	1,015.9
Non-current liabilities:
Long-term debt	679.7	688.2	1,311.6
Other liabilities	236.5	239.6	206.2
Deferred revenue	667.5	668.9	658.6
Deferred tax liabilities	74.2	92.3	117.2
Total liabilities	2,766.3	2,726.2	3,309.5
Shareholders’ equity:
Total shareholders’ equity	1,892.6	2,499.8	2,543.4
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	5,272.9	5,839.6	6,465.2
Consolidation, Eliminations
Current assets:
Cash and cash equivalents	0.0	0.0	0.0	0.0
Accounts receivable, held for sale	0.0
Accounts receivable, net	0.0	0.0	0.0
Intra-entity receivables, net	(245.1)	(169.8)	(87.0)
Other receivables	0.0	0.0	0.0
Other current 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	(245.1)	(169.8)	(87.0)
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	(3,166.8)	(4,919.8)	(4,552.1)
Intra-entity receivables, net	(3,225.0)	(3,259.0)	(4,045.3)
Other assets	0.0		0.0
Deferred tax assets	0.0		0.0
Retirement benefit asset	0.0		0.0
Total assets	(6,636.9)	(8,348.6)	(8,684.4)
Current liabilities:
Loans and overdrafts	0.0	0.0	0.0
Accounts payable	0.0	0.0	0.0
Intra-entity payables, net	(245.1)	(169.8)	(87.0)
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
Total current liabilities	(245.1)	(169.8)	(87.0)
Non-current liabilities:
Long-term debt			0.0
Intra-entity payables, net	(3,225.0)	(3,259.0)	(4,045.3)
Other liabilities			0.0
Deferred revenue			0.0
Deferred tax liabilities		0.0	0.0
Total liabilities	(3,470.1)	(3,428.8)	(4,132.3)
Shareholders’ equity:
Total shareholders’ equity	(3,166.8)	(4,919.8)	(4,552.1)
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	(6,636.9)	(8,348.6)	(8,684.4)
Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	102.5	150.5	72.9	70.3
Accounts receivable, held for sale	484.6
Accounts receivable, net	5.8	692.5	1,726.1
Intra-entity receivables, net	0.0	0.0	87.0
Other receivables	58.4	62.0	62.3
Other current assets	150.2	154.4	154.0
Income taxes	32.0	2.6	1.8
Inventories	2,360.6	2,201.3	2,362.0
Total current assets	3,194.1	3,263.3	4,466.1
Non-current assets:
Property, plant and equipment, net	839.7	870.1	825.6
Goodwill	206.4	516.4	512.5
Intangible assets, net	268.4	410.9	411.9
Investment in subsidiaries	579.4	1,163.6	734.5
Intra-entity receivables, net	0.0		0.0
Other assets	137.1	140.1	134.1
Deferred tax assets	0.8	1.3	0.5
Retirement benefit asset	39.3	39.8	33.9
Total assets	5,265.2	6,405.5	7,119.1
Current liabilities:
Loans and overdrafts	73.0	44.7	132.2
Accounts payable	257.2	202.2	170.6
Intra-entity payables, net	208.8	158.5	0.0
Accrued expenses and other current liabilities	403.7	397.5	343.9
Deferred revenue	272.1	276.2	272.1
Income taxes		36.7	36.3
Total current liabilities	1,214.8	1,115.8	955.1
Non-current liabilities:
Long-term debt	284.3	293.0	317.1
Intra-entity payables, net	3,225.0	3,259.0	4,045.3
Other liabilities	231.5	233.0	200.9
Deferred revenue	667.5	668.9	658.6
Deferred tax liabilities	57.5	76.7	117.1
Total liabilities	5,680.6	5,646.4	6,294.1
Shareholders’ equity:
Total shareholders’ equity	(415.4)	759.1	825.0
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	5,265.2	6,405.5	7,119.1
Non-Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	50.0	72.8	25.7	26.6
Accounts receivable, held for sale	0.0
Accounts receivable, net	1.0		0.2
Intra-entity receivables, net	237.3	166.9	0.0
Other receivables	25.2	25.2	26.3
Other current assets	3.0	3.8	4.9
Income taxes	23.2		0.0
Inventories	68.4	79.2	70.4
Total current assets	408.1	347.9	127.5
Non-current assets:
Property, plant and equipment, net	7.5	7.8	4.2
Goodwill	302.7	305.3	3.6
Intangible assets, net	74.8	70.6	0.0
Investment in subsidiaries	15.6	606.0	616.8
Intra-entity receivables, net	2,825.0	2,859.0	3,637.5
Other assets	29.9	31.1	31.0
Deferred tax assets		0.1	0.1
Retirement benefit asset	0.0		0.0
Total assets	3,663.6	4,227.8	4,420.7
Current liabilities:
Loans and overdrafts	0.0	0.0	0.0
Accounts payable	30.3	34.8	7.2
Intra-entity payables, net	0.0	0.0	70.8
Accrued expenses and other current liabilities	22.7	20.9	19.2
Deferred revenue	12.8	12.4	0.0
Income taxes		(16.9)	(2.1)
Total current liabilities	65.8	51.2	95.1
Non-current liabilities:
Long-term debt			600.0
Other liabilities	5.0	6.6	5.3
Deferred revenue			0.0
Deferred tax liabilities	16.7	15.6	0.1
Total liabilities	87.5	73.4	700.5
Shareholders’ equity:
Total shareholders’ equity	3,576.1	4,154.4	3,720.2
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	3,663.6	4,227.8	4,420.7
Signet Jewelers Limited | Reportable Legal Entities
Current assets:
Cash and cash equivalents	1.3	1.7	1.0	1.7
Accounts receivable, held for sale	0.0
Accounts receivable, net	0.0	0.0	0.0
Intra-entity receivables, net			0.0
Other receivables	0.0	0.0	0.0
Other current assets		0.0	0.1
Income taxes	0.0	0.0	0.0
Inventories	0.0	0.0	0.0
Total current assets	1.3	1.7	1.1
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	2,571.8	3,150.2	3,200.8
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	2,573.1	3,151.9	3,201.9
Current liabilities:
Loans and overdrafts	0.0	0.0	0.0
Accounts payable	0.0	0.0	0.0
Intra-entity payables, net	36.3	11.3	16.2
Accrued expenses and other current liabilities	30.2	27.2	30.0
Deferred revenue	0.0	0.0	0.0
Income taxes		0.0	0.0
Total current liabilities	66.5	38.5	46.2
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	66.5	38.5	46.2
Shareholders’ equity:
Total shareholders’ equity	1,892.6	2,499.8	2,543.4
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	2,573.1	3,151.9	3,201.9
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
Accounts receivable, net	0.0	0.0	0.0
Intra-entity receivables, net	7.8	2.9	0.0
Other receivables	0.0	0.0	0.0
Other current assets		0.0	0.0
Income taxes	0.0	0.0	0.0
Inventories	0.0	0.0	0.0
Total current assets	7.9	3.0	0.1
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	407.8
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	407.9	403.0	407.9
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	7.2
Deferred revenue	0.0	0.0	0.0
Income taxes		(0.2)	0.0
Total current liabilities	6.4	1.5	6.5
Non-current liabilities:
Long-term debt	395.4	395.2	394.5
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	401.8	396.7	401.0
Shareholders’ equity:
Total shareholders’ equity	6.1	6.3	6.9
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	407.9	403.0	407.9
Series A Redeemable Convertible Preferred Stock
Non-current liabilities:
Series A redeemable convertible preferred shares	614.0	613.6	612.3
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	614.0	613.6	612.3
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