Revenue recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 28, 2023	Jan. 29, 2022	Jan. 30, 2021
Disaggregation of Revenue [Line Items]
Total sales	$ 7,842.1	$ 7,826.0	$ 5,226.9
Bridal
Disaggregation of Revenue [Line Items]
Total sales	3,435.6	3,310.4	2,306.9
Fashion
Disaggregation of Revenue [Line Items]
Total sales	3,051.5	3,222.8	2,057.1
Watches
Disaggregation of Revenue [Line Items]
Total sales	385.5	399.6	254.1
Service
Disaggregation of Revenue [Line Items]
Total sales	706.6	645.3	386.3
Other
Disaggregation of Revenue [Line Items]
Total sales	262.9	247.9	222.5
Kay
Disaggregation of Revenue [Line Items]
Total sales	2,804.2	2,985.8	2,008.6
Zales
Disaggregation of Revenue [Line Items]
Total sales	1,445.0	1,624.8	1,121.6
Jared
Disaggregation of Revenue [Line Items]
Total sales	1,313.5	1,326.3	920.9
Digital banners
Disaggregation of Revenue [Line Items]
Total sales	571.8	422.8	301.4
Diamonds Direct
Disaggregation of Revenue [Line Items]
Total sales	467.1	132.5
Banter by Piercing Pagoda
Disaggregation of Revenue [Line Items]
Total sales	417.9	553.4	337.5
Peoples
Disaggregation of Revenue [Line Items]
Total sales	209.1	206.2	150.9
International
Disaggregation of Revenue [Line Items]
Total sales	470.1	492.4	355.9
Other
Disaggregation of Revenue [Line Items]
Total sales	143.4	81.8	30.1
Store
Disaggregation of Revenue [Line Items]
Total sales	6,114.5	6,245.6	4,011.8
eCommerce
Disaggregation of Revenue [Line Items]
Total sales	1,599.4	1,511.6	1,185.0
Other
Disaggregation of Revenue [Line Items]
Total sales	128.2	68.8	30.1
North America
Disaggregation of Revenue [Line Items]
Total sales	7,289.5	7,264.8	4,840.9
North America | Bridal
Disaggregation of Revenue [Line Items]
Total sales	3,230.8	3,087.6	2,140.5
North America | Fashion
Disaggregation of Revenue [Line Items]
Total sales	2,965.3	3,130.1	1,987.9
North America | Watches
Disaggregation of Revenue [Line Items]
Total sales	232.6	241.8	145.6
North America | Service
Disaggregation of Revenue [Line Items]
Total sales	680.4	626.2	374.5
North America | Other
Disaggregation of Revenue [Line Items]
Total sales	180.4	179.1	192.4
North America | Kay
Disaggregation of Revenue [Line Items]
Total sales	2,804.2	2,985.8	2,008.6
North America | Zales
Disaggregation of Revenue [Line Items]
Total sales	1,445.0	1,624.8	1,121.6
North America | Jared
Disaggregation of Revenue [Line Items]
Total sales	1,313.5	1,326.3	920.9
North America | Digital banners
Disaggregation of Revenue [Line Items]
Total sales	571.8	422.8	301.4
North America | Diamonds Direct
Disaggregation of Revenue [Line Items]
Total sales	467.1	132.5
North America | Banter by Piercing Pagoda
Disaggregation of Revenue [Line Items]
Total sales	417.9	553.4	337.5
North America | Peoples
Disaggregation of Revenue [Line Items]
Total sales	209.1	206.2	150.9
North America | International
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
North America | Other
Disaggregation of Revenue [Line Items]
Total sales	60.9	13.0	0.0
North America | Store
Disaggregation of Revenue [Line Items]
Total sales	5,728.5	5,867.9	3,772.9
North America | eCommerce
Disaggregation of Revenue [Line Items]
Total sales	1,515.3	1,396.9	1,068.0
North America | Other
Disaggregation of Revenue [Line Items]
Total sales	45.7	0.0	0.0
International
Disaggregation of Revenue [Line Items]
Total sales	470.1	492.4	355.9
International | Bridal
Disaggregation of Revenue [Line Items]
Total sales	204.8	222.8	166.4
International | Fashion
Disaggregation of Revenue [Line Items]
Total sales	86.2	92.7	69.2
International | Watches
Disaggregation of Revenue [Line Items]
Total sales	152.9	157.8	108.5
International | Service
Disaggregation of Revenue [Line Items]
Total sales	26.2	19.1	11.8
International | Other
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
International | Kay
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
International | Zales
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
International | Jared
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
International | Digital banners
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
International | Diamonds Direct
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0
International | Banter by Piercing Pagoda
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
International | Peoples
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
International | International
Disaggregation of Revenue [Line Items]
Total sales	470.1	492.4	355.9
International | Other
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
International | Store
Disaggregation of Revenue [Line Items]
Total sales	386.0	377.7	238.9
International | eCommerce
Disaggregation of Revenue [Line Items]
Total sales	84.1	114.7	117.0
International | Other
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other
Disaggregation of Revenue [Line Items]
Total sales	82.5	68.8	30.1
Other | Bridal
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other | Fashion
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other | Watches
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other | Service
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other | Other
Disaggregation of Revenue [Line Items]
Total sales	82.5	68.8	30.1
Other | Kay
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other | Zales
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other | Jared
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other | Digital banners
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other | Diamonds Direct
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0
Other | Banter by Piercing Pagoda
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other | Peoples
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other | International
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other | Other
Disaggregation of Revenue [Line Items]
Total sales	82.5	68.8	30.1
Other | Store
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other | eCommerce
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other | Other
Disaggregation of Revenue [Line Items]
Total sales	$ 82.5	$ 68.8	$ 30.1