Loans, overdrafts and long-term debt - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Oct. 29, 2016	Oct. 31, 2015	Oct. 29, 2016	Oct. 31, 2015	Jul. 30, 2016	Jul. 29, 2016	Jan. 30, 2016
Debt Instrument [Line Items]
Amortization of financing costs			$ 2,200,000	$ 2,600,000
Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity					$ 700,000,000	$ 400,000,000
Capitalized fees, current	$ 1,400,000		1,400,000
Capitalized fees	2,600,000		2,600,000
Accumulated amortization of noncurrent deferred finance costs	700,000	$ 300,000	700,000	300,000			$ 400,000
Amortization of financing costs	100,000	0	300,000	200,000
Letters of credit outstanding	$ 14,800,000	$ 21,300,000	$ 14,800,000	$ 21,300,000			28,800,000
Weighted average interest rate	1.68%	1.18%	1.68%	1.18%
Credit Facility | Term Loan
Debt Instrument [Line Items]
Capitalized fees, current	$ 700,000		$ 700,000
Capitalized fees	6,200,000		6,200,000
Accumulated amortization of noncurrent deferred finance costs	2,500,000	$ 1,600,000	2,500,000	$ 1,600,000			1,800,000
Amortization of financing costs	$ 200,000	$ 400,000	$ 700,000	$ 800,000
Weighted average interest rate	1.74%	1.46%	1.74%	1.46%
Face amount	$ 357,500,000.0		$ 357,500,000.0
Securitization Facility
Debt Instrument [Line Items]
Capitalized fees, current	600,000		600,000
Capitalized fees	3,400,000		3,400,000
Accumulated amortization of noncurrent deferred finance costs	3,000,000	$ 1,900,000	3,000,000	$ 1,900,000			2,400,000
Amortization of financing costs	$ 100,000	$ 300,000	$ 600,000	$ 1,000,000
Weighted average interest rate	1.98%	1.56%	1.98%	1.56%
Debt instrument, maturity period			2 years
Signet UK Finance plc | Senior Unsecured Notes Due in 2024
Debt Instrument [Line Items]
Capitalized fees	$ 7,000,000		$ 7,000,000
Accumulated amortization of noncurrent deferred finance costs	1,700,000	$ 1,000,000	1,700,000	$ 1,000,000			$ 1,200,000
Amortization of financing costs	200,000	$ 200,000	500,000	$ 500,000
Face amount	$ 400,000,000		$ 400,000,000
Stated interest rate	4.70%		4.70%
Year One | Credit Facility | Term Loan
Debt Instrument [Line Items]
Quarterly repayment rate	5.00%		5.00%
Year Two | Credit Facility | Term Loan
Debt Instrument [Line Items]
Quarterly repayment rate	7.50%		7.50%
Year Three | Credit Facility | Term Loan
Debt Instrument [Line Items]
Quarterly repayment rate	10.00%		10.00%
Year Four | Credit Facility | Term Loan
Debt Instrument [Line Items]
Quarterly repayment rate	12.50%		12.50%
Year Five | Credit Facility | Term Loan
Debt Instrument [Line Items]
Quarterly repayment rate	15.00%		15.00%