Loans, overdrafts and long-term debt - Additional Information (Details) - USD ($)	3 Months Ended
	May 04, 2019	May 05, 2018	Feb. 02, 2019
Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	$ 700,000,000
Capitalized fees	2,600,000
Accumulated amortization of noncurrent deferred finance costs	1,700,000	$ 1,300,000	$ 1,600,000
Amortization of financing costs	100,000	100,000
Letters of credit outstanding	14,600,000	$ 14,500,000	14,600,000
Weighted average interest rate		3.30%
Credit Facility | Term Loan
Debt Instrument [Line Items]
Face amount	357,500,000.0
Capitalized fees	6,200,000
Accumulated amortization of noncurrent deferred finance costs	4,700,000	$ 3,700,000	4,300,000
Amortization of financing costs	$ 400,000	$ 200,000
Weighted average interest rate	4.37%	3.10%
Signet UK Finance plc | Senior Unsecured Notes Due in 2024
Debt Instrument [Line Items]
Face amount	$ 400,000,000
Capitalized fees	7,000,000
Accumulated amortization of noncurrent deferred finance costs	3,400,000	$ 2,700,000	$ 3,300,000
Amortization of financing costs	$ 100,000	$ 100,000
Stated interest rate	4.70%