Loans, overdrafts and long-term debt - Additional Information (Details) - USD ($)	3 Months Ended
	Apr. 29, 2017	Apr. 30, 2016	Jan. 28, 2017
Debt Instrument [Line Items]
Amortization of financing costs	$ 600,000	$ 900,000
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	900,000	500,000	$ 800,000
Amortization of financing costs	100,000	100,000
Letters of credit outstanding	$ 15,300,000	$ 23,800,000	15,300,000
Weighted average interest rate	2.11%	1.42%
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	2,900,000	$ 2,100,000	2,700,000
Amortization of financing costs	$ 200,000	$ 300,000
Weighted average interest rate	2.13%	1.71%
Securitization Facility
Debt Instrument [Line Items]
Capitalized fees	$ 3,400,000
Accumulated amortization of noncurrent deferred finance costs	3,100,000	$ 2,700,000	3,100,000
Amortization of financing costs	$ 0	$ 300,000
Weighted average interest rate	2.39%	1.90%
Debt instrument, maturity period	2 years
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	2,100,000	$ 1,400,000	$ 1,900,000
Amortization of financing costs	$ 200,000	$ 200,000
Stated interest rate	4.70%