Revenue recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 30, 2021	Oct. 31, 2020	Oct. 30, 2021	Oct. 31, 2020
Disaggregation of Revenue [Line Items]
Sales	$ 1,537.8	$ 1,300.3	$ 5,014.7	$ 3,040.4
Bridal
Disaggregation of Revenue [Line Items]
Sales	698.2	612.5	2,211.3	1,400.6
Fashion
Disaggregation of Revenue [Line Items]
Sales	547.9	420.2	1,920.4	1,037.9
Watches
Disaggregation of Revenue [Line Items]
Sales	92.7	67.0	256.4	155.2
Other
Disaggregation of Revenue [Line Items]
Sales	199.0	200.6	626.6	446.7
Store
Disaggregation of Revenue [Line Items]
Sales	1,242.0	1,050.8	4,011.3	2,346.0
Kay
Disaggregation of Revenue [Line Items]
Sales	573.4	490.5	1,923.8	1,149.0
Zales
Disaggregation of Revenue [Line Items]
Sales	291.9	251.4	1,030.0	618.8
Jared
Disaggregation of Revenue [Line Items]
Sales	277.1	232.7	873.1	546.6
Piercing Pagoda
Disaggregation of Revenue [Line Items]
Sales	111.4	93.7	399.0	204.4
James Allen
Disaggregation of Revenue [Line Items]
Sales	90.4	76.6	300.7	184.7
Peoples
Disaggregation of Revenue [Line Items]
Sales	45.9	37.8	121.9	83.3
International segment
Disaggregation of Revenue [Line Items]
Sales	120.9	106.9	309.0	232.8
Other
Disaggregation of Revenue [Line Items]
Sales	26.8	10.7	57.2	20.8
E-commerce
Disaggregation of Revenue [Line Items]
Sales	273.1	238.8	955.6	673.6
Other
Disaggregation of Revenue [Line Items]
Sales	22.7	10.7	47.8	20.8
North America
Disaggregation of Revenue [Line Items]
Sales	1,394.2	1,182.7	4,657.9	2,786.8
North America | Bridal
Disaggregation of Revenue [Line Items]
Sales	640.9	564.5	2,064.5	1,295.7
North America | Fashion
Disaggregation of Revenue [Line Items]
Sales	524.6	400.7	1,866.7	993.1
North America | Watches
Disaggregation of Revenue [Line Items]
Sales	48.7	33.6	154.2	81.9
North America | Other
Disaggregation of Revenue [Line Items]
Sales	180.0	183.9	572.5	416.1
North America | Store
Disaggregation of Revenue [Line Items]
Sales	1,142.6	963.7	3,775.5	2,170.2
North America | Kay
Disaggregation of Revenue [Line Items]
Sales	573.4	490.5	1,923.8	1,149.0
North America | Zales
Disaggregation of Revenue [Line Items]
Sales	291.9	251.4	1,030.0	618.8
North America | Jared
Disaggregation of Revenue [Line Items]
Sales	277.1	232.7	873.1	546.6
North America | Piercing Pagoda
Disaggregation of Revenue [Line Items]
Sales	111.4	93.7	399.0	204.4
North America | James Allen
Disaggregation of Revenue [Line Items]
Sales	90.4	76.6	300.7	184.7
North America | Peoples
Disaggregation of Revenue [Line Items]
Sales	45.9	37.8	121.9	83.3
North America | International segment
Disaggregation of Revenue [Line Items]
Sales	0.0		0.0	0.0
North America | Other
Disaggregation of Revenue [Line Items]
Sales	4.1	0.0	9.4
North America | E-commerce
Disaggregation of Revenue [Line Items]
Sales	251.6	219.0	882.4	616.6
North America | Other
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
International segment
Disaggregation of Revenue [Line Items]
Sales	120.9	106.9	309.0	232.8
International segment | Bridal
Disaggregation of Revenue [Line Items]
Sales	57.3	48.0	146.8	104.9
International segment | Fashion
Disaggregation of Revenue [Line Items]
Sales	23.3	19.5	53.7	44.8
International segment | Watches
Disaggregation of Revenue [Line Items]
Sales	44.0	33.4	102.2	73.3
International segment | Other
Disaggregation of Revenue [Line Items]
Sales	(3.7)	6.0	6.3	9.8
International segment | Store
Disaggregation of Revenue [Line Items]
Sales	99.4	87.1	235.8	175.8
International segment | Kay
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
International segment | Zales
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
International segment | Jared
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
International segment | Piercing Pagoda
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
International segment | James Allen
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
International segment | Peoples
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
International segment | International segment
Disaggregation of Revenue [Line Items]
Sales	120.9	106.9	309.0	232.8
International segment | Other
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
International segment | E-commerce
Disaggregation of Revenue [Line Items]
Sales	21.5	19.8	73.2	57.0
International segment | Other
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Other
Disaggregation of Revenue [Line Items]
Sales	22.7	10.7	47.8	20.8
Other | Bridal
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Other | Fashion
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Other | Watches
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Other | Other
Disaggregation of Revenue [Line Items]
Sales	22.7	10.7	47.8	20.8
Other | Store
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Other | Kay
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Other | Zales
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Other | Jared
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Other | Piercing Pagoda
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Other | James Allen
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Other | Peoples
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Other | International segment
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Other | Other
Disaggregation of Revenue [Line Items]
Sales	22.7	10.7	47.8	20.8
Other | E-commerce
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Other | Other
Disaggregation of Revenue [Line Items]
Sales	$ 22.7	$ 10.7	$ 47.8	$ 20.8