Loans, overdrafts and long-term debt - Additional Information (Detail)		3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 27, 2019 USD ($)	Oct. 28, 2017 USD ($)	Oct. 28, 2017 USD ($)	Feb. 01, 2020 USD ($)	Feb. 02, 2019 USD ($)	Feb. 03, 2018 USD ($)	Sep. 12, 2017 USD ($)	May 19, 2014 USD ($)
Debt Instrument [Line Items]
Repayments of senior debt				$ 241,500,000	$ 0	$ 0
Gain on extinguishment of debt				6,200,000	0	0
Long-term debt, gross				580,600,000
Payment of debt issuance costs				9,300,000	0	0
Long-term debt				613,100,000	734,000,000.0
Senior Unsecured Notes Due in 2024 | Signet UK Finance plc
Debt Instrument [Line Items]
Face amount								$ 400,000,000
Stated interest rate								4.70%
Amortization related to capitalized fees						700,000
Other loans and bank overdrafts
Debt Instrument [Line Items]
Long-term debt, gross				87,500,000
Credit Facility
Debt Instrument [Line Items]
Unamortized debt issuance costs				2,000,000.0
Senior Unsecured Notes Due in 2024 | Senior Notes
Debt Instrument [Line Items]
Unamortized debt issuance costs				2,600,000
Repayments of senior debt	$ 239,600,000
Redemption price per $1,000 of principal amount	950.00
Gain on extinguishment of debt				8,200,000
Payment for debt extinguishment third party fees				1,900,000
Unamortized debt issuance expense				1,100,000	3,700,000
Amortization related to capitalized fees				600,000	700,000
Long-term debt				147,500,000	399,000,000.0
Senior Asset-Based Credit Facility | Line of Credit
Debt Instrument [Line Items]
Amortization related to capitalized fees				600,000
Capitalized fees				9,300,000
Securitization Facility
Debt Instrument [Line Items]
Unamortized debt issuance costs		$ 200,000
Face amount		$ 600,000,000	$ 600,000,000
Amortization related to capitalized fees			$ 300,000
Capitalized fees						3,400,000
Capitalized issuance costs written off						3,400,000
Term Loan Facility | Credit Facility | Line of Credit
Debt Instrument [Line Items]
Long-term debt				0	294,900,000
Term Loan Facility | Senior Asset-Based Credit Facility | Line of Credit
Debt Instrument [Line Items]
Face amount				$ 100,000,000.0
Interest rate at period end				2.80%
Capitalized fees				$ 600,000
Long-term debt				100,000,000.0	0
Revolving Credit Facility | Senior Asset-Based Credit Facility | Line of Credit
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	$ 1,500,000,000
Stand-by letters of credit				14,900,000
Line of credit facility, remaining borrowing capacity				$ 1,200,000,000
Covenant, minimum coverage ratio				1.00
Debt covenant, fixed covenant ratio threshold				$ 150,000,000
Debt covenant, payments restrictions threshold				$ 260,000,000
Interest rate at period end				3.60%
Capitalized fees				$ 8,700,000
Long-term debt				$ 270,000,000.0	$ 0
R2Net Inc. | Bridge Loan
Debt Instrument [Line Items]
Long-term debt, gross							$ 350,000,000.0
Payment of debt issuance costs						1,400,000
Interest expense, debt						$ 900,000