Restructuring Plans - Restructuring and Related Costs (Details) - USD ($) $ in Millions	3 Months Ended		39 Months Ended
	May 01, 2021	May 02, 2020	May 01, 2021
Restructuring Cost and Reserve [Line Items]
Total Signet Path to Brilliance Plan expenses	$ (0.7)	$ 12.7
Signet Path to Brilliance
Restructuring Cost and Reserve [Line Items]
Total Signet Path to Brilliance Plan expenses	(0.7)	12.3	$ 251.9
Signet Path to Brilliance | Cost of sales
Restructuring Cost and Reserve [Line Items]
Inventory charges	0.0	(0.4)
Signet Path to Brilliance | Restructuring Charges
Restructuring Cost and Reserve [Line Items]
Other Plan related expenses	(0.7)	$ 12.7
Inventory charges | Signet Path to Brilliance
Restructuring Cost and Reserve [Line Items]
Total Signet Path to Brilliance Plan expenses	0.0		72.8
Termination benefits | Signet Path to Brilliance
Restructuring Cost and Reserve [Line Items]
Total Signet Path to Brilliance Plan expenses	(0.7)		49.2
Store closure and other costs | Signet Path to Brilliance
Restructuring Cost and Reserve [Line Items]
Total Signet Path to Brilliance Plan expenses	$ 0.0		$ 129.9