Loans, overdrafts and long-term debt - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Nov. 03, 2018	Oct. 28, 2017	Nov. 03, 2018	Oct. 28, 2017	Feb. 03, 2018
Debt Instrument [Line Items]
Amortization of financing costs			$ 1,500,000	$ 3,200,000
Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	$ 700,000,000		700,000,000
Capitalized fees	2,600,000		2,600,000
Accumulated amortization of noncurrent deferred finance costs	1,500,000	$ 1,100,000	1,500,000	1,100,000	$ 1,200,000
Amortization of financing costs	100,000	100,000	300,000	300,000
Letters of credit outstanding	$ 14,600,000	$ 15,700,000	$ 14,600,000	$ 15,700,000	15,700,000
Weighted average interest rate	3.62%	2.45%	3.62%	2.45%
Credit Facility | Term Loan
Debt Instrument [Line Items]
Face amount	$ 357,500,000.0		$ 357,500,000.0
Capitalized fees	6,200,000		6,200,000
Accumulated amortization of noncurrent deferred finance costs	4,100,000	$ 3,300,000	4,100,000	$ 3,300,000	3,500,000
Amortization of financing costs	$ 200,000	$ 200,000	$ 600,000	$ 600,000
Weighted average interest rate	3.44%	2.34%	3.44%	2.34%
Signet UK Finance plc | Senior Unsecured Notes Due in 2024
Debt Instrument [Line Items]
Face amount	$ 400,000,000		$ 400,000,000
Capitalized fees	7,000,000		7,000,000
Accumulated amortization of noncurrent deferred finance costs	3,100,000	$ 2,400,000	3,100,000	$ 2,400,000	$ 2,600,000
Amortization of financing costs	$ 200,000	$ 200,000	$ 500,000	$ 500,000
Stated interest rate	4.70%		4.70%