Condensed Consolidating Financial Information - Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Millions	Feb. 03, 2018	Jan. 28, 2017	Jan. 30, 2016	Jan. 31, 2015
Current assets:
Cash and cash equivalents	$ 225.1	$ 98.7	$ 137.7	$ 193.6
Accounts receivable, net	692.5	1,858.0
Intra-entity receivables, net	0.0	0.0
Other receivables	87.2	95.9
Other current assets	158.2	136.3
Income taxes	2.6	4.4
Inventories	2,280.5	2,449.3
Total current assets	3,446.1	4,642.6
Non-current assets:
Property, plant and equipment, net	877.9	822.9
Goodwill	821.7	517.6	515.5
Intangible assets, net	481.5	417.0
Investment in subsidiaries	0.0
Intra-entity receivables, net	0.0
Other assets	171.2	165.1
Deferred tax assets	1.4	0.7
Retirement benefit asset	39.8	31.9
Total assets	5,839.6	6,597.8
Current liabilities:
Loans and overdrafts	44.0	91.1
Accounts payable	237.0	255.7
Intra-entity payables, net		0.0
Accrued expenses and other current liabilities	448.0	478.2
Deferred revenue	288.6	276.9
Income taxes	19.6	101.8
Total current liabilities	1,037.2	1,203.7
Non-current liabilities:
Long-term debt	688.2	1,317.9
Other liabilities	239.6	213.7
Deferred revenue	668.9	659.0
Deferred tax liabilities	92.3	101.4
Total liabilities	2,726.2	3,495.7
Series A redeemable convertible preferred shares		611.9
Shareholders’ equity:
Total shareholders’ equity	2,499.8	2,490.2	3,060.7	2,810.4
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	5,839.6	6,597.8
Consolidation, Eliminations
Current assets:
Cash and cash equivalents	0.0	0.0	0.0	0.0
Accounts receivable, net	0.0	0.0
Intra-entity receivables, net	(169.8)	(157.8)
Other receivables	0.0	0.0
Other current assets	0.0	0.0
Income taxes	0.0	0.0
Inventories	0.0	0.0
Total current assets	(169.8)	(157.8)
Non-current assets:
Property, plant and equipment, net	0.0
Goodwill	0.0
Intangible assets, net	0.0	0.0
Investment in subsidiaries	(4,919.8)	(4,430.1)
Intra-entity receivables, net	(3,259.0)	(4,050.0)
Other assets	0.0
Deferred tax assets	0.0
Retirement benefit asset	0.0
Total assets	(8,348.6)	(8,637.9)
Current liabilities:
Loans and overdrafts	0.0	0.0
Accounts payable	0.0	0.0
Intra-entity payables, net	(169.8)	(157.8)
Accrued expenses and other current liabilities	0.0	0.0
Deferred revenue	0.0	0.0
Income taxes	0.0	0.0
Total current liabilities	(169.8)	(157.8)
Non-current liabilities:
Intra-entity payables, net	(3,259.0)	(4,050.0)
Total liabilities	(3,428.8)	(4,207.8)
Series A redeemable convertible preferred shares		0.0
Shareholders’ equity:
Total shareholders’ equity	(4,919.8)	(4,430.1)
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	(8,348.6)	(8,637.9)
Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	150.5	70.3	102.0	166.5
Accounts receivable, net	692.5	1,858.0
Intra-entity receivables, net	0.0	145.1
Other receivables	62.0	71.1
Other current assets	154.4	131.4
Income taxes	2.6	4.4
Inventories	2,201.3	2,371.8
Total current assets	3,263.3	4,652.1
Non-current assets:
Property, plant and equipment, net	870.1	818.5
Goodwill	516.4	514.0
Intangible assets, net	410.9	417.0
Investment in subsidiaries	1,163.6	721.6
Intra-entity receivables, net	0.0
Other assets	140.1	134.8
Deferred tax assets	1.3	0.6
Retirement benefit asset	39.8	31.9
Total assets	6,405.5	7,290.5
Current liabilities:
Loans and overdrafts	44.7	91.8
Accounts payable	202.2	248.2
Intra-entity payables, net	158.5
Accrued expenses and other current liabilities	397.5	429.2
Deferred revenue	276.2	275.5
Income taxes	36.7	115.5
Total current liabilities	1,115.8	1,160.2
Non-current liabilities:
Long-term debt	293.0	323.6
Intra-entity payables, net	3,259.0	4,050.0
Other liabilities	233.0	208.7
Deferred revenue	668.9	659.0
Deferred tax liabilities	76.7	101.4
Total liabilities	5,646.4	6,502.9
Shareholders’ equity:
Total shareholders’ equity	759.1	787.6
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	6,405.5	7,290.5
Non-Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	72.8	26.6	33.7	24.9
Intra-entity receivables, net	166.9
Other receivables	25.2	24.8
Other current assets	3.8	4.9
Income taxes	0.0
Inventories	79.2	77.5
Total current assets	347.9	133.8
Non-current assets:
Property, plant and equipment, net	7.8	4.4
Goodwill	305.3	3.6
Intangible assets, net	70.6	0.0
Investment in subsidiaries	606.0	590.9
Intra-entity receivables, net	2,859.0	3,647.1
Other assets	31.1	30.3
Deferred tax assets	0.1	0.1
Retirement benefit asset	0.0
Total assets	4,227.8	4,410.2
Current liabilities:
Loans and overdrafts	0.0	0.0
Accounts payable	34.8	7.5
Intra-entity payables, net	0.0	157.8
Accrued expenses and other current liabilities	20.9	16.6
Deferred revenue	12.4	1.4
Income taxes	(16.9)	(13.5)
Total current liabilities	51.2	169.8
Non-current liabilities:
Long-term debt		600.0
Other liabilities	6.6	5.0
Deferred tax liabilities	15.6
Total liabilities	73.4	774.8
Shareholders’ equity:
Total shareholders’ equity	4,154.4	3,635.4
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	4,227.8	4,410.2
Signet Jewelers Limited | Reportable Legal Entities
Current assets:
Cash and cash equivalents	1.7	1.7	1.9	2.1
Accounts receivable, net	0.0	0.0
Intra-entity receivables, net		12.7
Other receivables	0.0	0.0
Other current assets		0.0
Income taxes	0.0	0.0
Inventories	0.0	0.0
Total current assets	1.7	14.4
Non-current assets:
Property, plant and equipment, net	0.0
Goodwill	0.0
Intangible assets, net	0.0	0.0
Investment in subsidiaries	3,150.2	3,117.6
Intra-entity receivables, net	0.0
Other assets	0.0
Deferred tax assets	0.0
Retirement benefit asset	0.0
Total assets	3,151.9	3,132.0
Current liabilities:
Loans and overdrafts	0.0	0.0
Accounts payable	0.0	0.0
Intra-entity payables, net	11.3	0.0
Accrued expenses and other current liabilities	27.2	29.9
Deferred revenue	0.0	0.0
Income taxes	0.0	0.0
Total current liabilities	38.5	29.9
Non-current liabilities:
Total liabilities	38.5	29.9
Shareholders’ equity:
Total shareholders’ equity	2,499.8	2,490.2
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	3,151.9	3,132.0
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
Intra-entity receivables, net	2.9	0.0
Other receivables	0.0	0.0
Other current assets		0.0
Income taxes	0.0	0.0
Inventories	0.0	0.0
Total current assets	3.0	0.1
Non-current assets:
Property, plant and equipment, net	0.0	0.0
Goodwill	0.0	0.0
Intangible assets, net	0.0	0.0
Investment in subsidiaries	0.0	0.0
Intra-entity receivables, net	400.0	402.9
Other assets		0.0
Deferred tax assets	0.0	0.0
Retirement benefit asset	0.0	0.0
Total assets	403.0	403.0
Current liabilities:
Loans and overdrafts	(0.7)	(0.7)
Accounts payable	0.0	0.0
Intra-entity payables, net	0.0	0.0
Accrued expenses and other current liabilities	2.4	2.5
Deferred revenue	0.0	0.0
Income taxes	(0.2)	(0.2)
Total current liabilities	1.5	1.6
Non-current liabilities:
Long-term debt	395.2	394.3
Intra-entity payables, net		0.0
Other liabilities		0.0
Deferred revenue		0.0
Total liabilities	396.7	395.9
Shareholders’ equity:
Total shareholders’ equity	6.3	7.1
Total liabilities, redeemable convertible preferred shares and shareholders’ equity	403.0	403.0
Series A Redeemable Convertible Preferred Stock
Non-current liabilities:
Series A redeemable convertible preferred shares	613.6	611.9
Series A Redeemable Convertible Preferred Stock | Consolidation, Eliminations
Non-current liabilities:
Series A redeemable convertible preferred shares	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
Series A Redeemable Convertible Preferred Stock | Signet Jewelers Limited | Reportable Legal Entities
Non-current liabilities:
Series A redeemable convertible preferred shares	613.6	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