Condensed consolidating financial information - Condensed consolidated balance sheet (Details) - USD ($) $ in Millions	Apr. 29, 2017	Jan. 28, 2017	Apr. 30, 2016	Jan. 30, 2016
Current assets:
Cash and cash equivalents	$ 99.7	$ 98.7	$ 113.0	$ 137.7
Accounts receivable, net	1,726.3	1,858.0	1,689.3
Intra-entity receivables, net	0.0	0.0	0.0
Other receivables	88.6	95.9	63.7
Other current assets	159.0	136.3	161.2
Income taxes	1.8	4.4	1.4
Inventories	2,432.4	2,449.3	2,512.6
Total current assets	4,507.8	4,642.6	4,541.2
Non-current assets:
Property, plant and equipment, net	829.8	822.9	725.7
Goodwill	516.1	517.6	519.7	515.5
Intangible assets, net	411.9	417.0	430.4
Investment in subsidiaries	0.0		0.0
Intra-entity receivables, net	0.0		0.0
Other assets	165.1	165.1	157.2
Deferred tax assets	0.6	0.7	0.0
Retirement benefit asset	33.9	31.9	53.5
Total assets	6,465.2	6,597.8	6,427.7
Current liabilities:
Loans and overdrafts	131.5	91.1	110.1
Accounts payable	177.8	255.7	255.7
Intra-entity payables, net		0.0	0.0
Accrued expenses and other current liabilities	400.3	478.2	409.5
Deferred revenue	272.1	276.9	261.4
Income taxes	34.2	101.8	19.1
Total current liabilities	1,015.9	1,203.7	1,055.8
Non-current liabilities:
Long-term debt	1,311.6	1,317.9	1,311.5
Intra-entity payables, net			0.0
Other liabilities	206.2	213.7	229.7
Deferred revenue	658.6	659.0	644.4
Deferred tax liabilities	117.2	101.4	88.1
Total liabilities	3,309.5	3,495.7	3,329.5
Shareholders’ equity:
Total shareholders’ equity	2,543.4	2,490.2	3,098.2
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	6,465.2	6,597.8	6,427.7
Consolidation, Eliminations
Current assets:
Cash and cash equivalents	0.0	0.0	0.0	0.0
Accounts receivable, net	0.0	0.0	0.0
Intra-entity receivables, net	(87.0)	(157.8)	(335.0)
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	(87.0)	(157.8)	(335.0)
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	(4,552.1)	(4,430.1)	(4,199.7)
Intra-entity receivables, net	(4,045.3)	(4,050.0)	(4,065.0)
Other assets	0.0		0.0
Deferred tax assets	0.0		0.0
Retirement benefit asset	0.0		0.0
Total assets	(8,684.4)	(8,637.9)	(8,599.7)
Current liabilities:
Loans and overdrafts	0.0	0.0	0.0
Accounts payable	0.0	0.0	0.0
Intra-entity payables, net	(87.0)	(157.8)	(335.0)
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	0.0
Total current liabilities	(87.0)	(157.8)	(335.0)
Non-current liabilities:
Intra-entity payables, net	(4,045.3)	(4,050.0)	(4,065.0)
Other liabilities			0.0
Deferred revenue			0.0
Deferred tax liabilities		0.0	0.0
Total liabilities	(4,132.3)	(4,207.8)	(4,400.0)
Shareholders’ equity:
Total shareholders’ equity	(4,552.1)	(4,430.1)	(4,199.7)
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	(8,684.4)	(8,637.9)	(8,599.7)
Signet Jewelers Limited | Reportable Legal Entities
Current assets:
Cash and cash equivalents	1.0	1.7	0.6	1.9
Accounts receivable, net	0.0	0.0	0.0
Intra-entity receivables, net		12.7	133.0
Other receivables	0.0	0.0	0.0
Other current assets	0.1	0.0	0.1
Income taxes	0.0	0.0	0.0
Inventories	0.0	0.0	0.0
Total current assets	1.1	14.4	133.7
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	3,200.8	3,117.6	2,985.1
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	3,201.9	3,132.0	3,118.8
Current liabilities:
Loans and overdrafts	0.0	0.0	0.0
Accounts payable	0.0	0.0	0.0
Intra-entity payables, net	16.2	0.0	0.0
Accrued expenses and other current liabilities	30.0	29.9	20.6
Deferred revenue	0.0	0.0	0.0
Income taxes	0.0	0.0	0.0
Total current liabilities	46.2	29.9	20.6
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	46.2	29.9	20.6
Shareholders’ equity:
Total shareholders’ equity	2,543.4	2,490.2	3,098.2
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	3,201.9	3,132.0	3,118.8
Signet UK Finance plc | Reportable Legal Entities
Current assets:
Cash and cash equivalents	0.1	0.1	0.1	0.1
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		0.0	0.0
Income taxes	0.0	0.0	0.0
Inventories	0.0	0.0	0.0
Total current assets	0.1	0.1	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	407.8	402.9	407.5
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	407.6
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	7.2	2.5	7.1
Deferred revenue	0.0	0.0	0.0
Income taxes		(0.2)	0.0
Total current liabilities	6.5	1.6	6.4
Non-current liabilities:
Long-term debt	394.5	394.3	393.7
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	401.0	395.9	400.1
Shareholders’ equity:
Total shareholders’ equity	6.9	7.1	7.5
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	407.9	403.0	407.6
Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	72.9	70.3	87.6	102.0
Accounts receivable, net	1,726.1	1,858.0	1,685.1
Intra-entity receivables, net	87.0	145.1	0.0
Other receivables	62.3	71.1	44.9
Other current assets	154.0	131.4	155.8
Income taxes	1.8	4.4	1.4
Inventories	2,362.0	2,371.8	2,433.9
Total current assets	4,466.1	4,652.1	4,408.7
Non-current assets:
Property, plant and equipment, net	825.6	818.5	720.5
Goodwill	512.5	514.0	516.1
Intangible assets, net	411.9	417.0	430.4
Investment in subsidiaries	734.5	721.6	687.4
Intra-entity receivables, net	0.0		0.0
Other assets	134.1	134.8	127.0
Deferred tax assets	0.5	0.6	0.0
Retirement benefit asset	33.9	31.9	53.5
Total assets	7,119.1	7,290.5	6,943.6
Current liabilities:
Loans and overdrafts	132.2	91.8	110.8
Accounts payable	170.6	248.2	248.3
Intra-entity payables, net			335.0
Accrued expenses and other current liabilities	343.9	429.2	369.0
Deferred revenue	272.1	275.5	261.4
Income taxes	36.3	115.5	22.6
Total current liabilities	955.1	1,160.2	1,347.1
Non-current liabilities:
Long-term debt	317.1	323.6	317.8
Intra-entity payables, net	4,045.3	4,050.0	4,065.0
Other liabilities	200.9	208.7	223.5
Deferred revenue	658.6	659.0	644.4
Deferred tax liabilities	117.1	101.4	88.3
Total liabilities	6,294.1	6,502.9	6,686.1
Shareholders’ equity:
Total shareholders’ equity	825.0	787.6	257.5
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	7,119.1	7,290.5	6,943.6
Non-Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	25.7	26.6	24.7	$ 33.7
Accounts receivable, net	0.2		4.2
Intra-entity receivables, net			202.0
Other receivables	26.3	24.8	18.8
Other current assets	4.9	4.9	5.3
Income taxes	0.0		0.0
Inventories	70.4	77.5	78.7
Total current assets	127.5	133.8	333.7
Non-current assets:
Property, plant and equipment, net	4.2	4.4	5.2
Goodwill	3.6	3.6	3.6
Intangible assets, net	0.0	0.0	0.0
Investment in subsidiaries	616.8	590.9	527.2
Intra-entity receivables, net	3,637.5	3,647.1	3,657.5
Other assets	31.0	30.3	30.2
Deferred tax assets	0.1	0.1	0.0
Retirement benefit asset	0.0		0.0
Total assets	4,420.7	4,410.2	4,557.4
Current liabilities:
Loans and overdrafts	0.0	0.0	0.0
Accounts payable	7.2	7.5	7.4
Intra-entity payables, net	70.8	157.8	0.0
Accrued expenses and other current liabilities	19.2	16.6	12.8
Deferred revenue	0.0	1.4	0.0
Income taxes	(2.1)	(13.5)	(3.5)
Total current liabilities	95.1	169.8	16.7
Non-current liabilities:
Long-term debt	600.0	600.0	600.0
Intra-entity payables, net			0.0
Other liabilities	5.3	5.0	6.2
Deferred revenue			0.0
Deferred tax liabilities	0.1	0.0	(0.2)
Total liabilities	700.5	774.8	622.7
Shareholders’ equity:
Total shareholders’ equity	3,720.2	3,635.4	3,934.7
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	4,420.7	4,410.2	4,557.4
Series A Redeemable Convertible Preferred Stock
Non-current liabilities:
Series A redeemable convertible preferred shares	612.3	611.9	$ 0.0
Series A Redeemable Convertible Preferred Stock | Consolidation, Eliminations
Non-current liabilities:
Series A redeemable convertible preferred shares	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	612.3	611.9
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
Series A Redeemable Convertible Preferred Stock | Guarantor Subsidiaries | Reportable Legal Entities
Non-current liabilities:
Series A redeemable convertible preferred shares	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