Retirement plans - Narrative (Details) £ in Thousands, $ in Millions			6 Months Ended
	Jul. 29, 2021 GBP (£) employee	Jul. 29, 2021 USD ($) employee	Jul. 31, 2021 USD ($)
Defined Contribution Plan [Line Items]
Number of pension scheme members | employee	1,909	1,909
Signet Group Limited | Pension scheme
Defined Contribution Plan [Line Items]
Defined benefit plan, expected future employer contributions, amount	£ 16,850	$ 23.4
Defined benefit plan, initial contribution amount	£ 7,000	$ 9.7
Minimum | Pension scheme
Defined Contribution Plan [Line Items]
Defined benefit plan, net periodic benefit cost, expected gain (loss) due to settlement			$ (125.0)
Maximum | Pension scheme
Defined Contribution Plan [Line Items]
Defined benefit plan, net periodic benefit cost, expected gain (loss) due to settlement			$ (150.0)