Revenue recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 29, 2022	Jan. 30, 2021	Feb. 01, 2020
Disaggregation of Revenue [Line Items]
Total sales	$ 7,826.0	$ 5,226.9	$ 6,137.1
Bridal
Disaggregation of Revenue [Line Items]
Total sales	3,310.4	2,306.9	2,617.7
Fashion
Disaggregation of Revenue [Line Items]
Total sales	3,222.8	2,057.1	2,241.5
Watches
Disaggregation of Revenue [Line Items]
Total sales	399.6	254.1	384.0
Other
Disaggregation of Revenue [Line Items]
Total sales	893.2	608.8	893.9
Store
Disaggregation of Revenue [Line Items]
Total sales	6,245.6	4,011.8	5,333.4
Kay
Disaggregation of Revenue [Line Items]
Total sales	2,985.8	2,008.6	2,414.0
Zales
Disaggregation of Revenue [Line Items]
Total sales	1,624.8	1,121.6	1,276.8
Jared
Disaggregation of Revenue [Line Items]
Total sales	1,326.3	920.9	1,088.1
Banter by Piercing Pagoda
Disaggregation of Revenue [Line Items]
Total sales	553.4	337.5	331.7
Diamonds Direct (2)
Disaggregation of Revenue [Line Items]
Total sales	132.5
James Allen
Disaggregation of Revenue [Line Items]
Total sales	422.8	301.4	250.6
Peoples
Disaggregation of Revenue [Line Items]
Total sales	206.2	150.9	204.6
International
Disaggregation of Revenue [Line Items]
Total sales	492.4	355.9	518.0
Other
Disaggregation of Revenue [Line Items]
Total sales	81.8	30.1	53.3
eCommerce
Disaggregation of Revenue [Line Items]
Total sales	1,511.6	1,185.0	750.4
Other
Disaggregation of Revenue [Line Items]
Total sales	68.8	30.1	53.3
North America
Disaggregation of Revenue [Line Items]
Total sales	7,264.8	4,840.9	5,565.8
North America | Bridal
Disaggregation of Revenue [Line Items]
Total sales	3,087.6	2,140.5	2,403.4
North America | Fashion
Disaggregation of Revenue [Line Items]
Total sales	3,130.1	1,987.9	2,131.0
North America | Watches
Disaggregation of Revenue [Line Items]
Total sales	241.8	145.6	214.9
North America | Other
Disaggregation of Revenue [Line Items]
Total sales	805.3	566.9	816.5
North America | Store
Disaggregation of Revenue [Line Items]
Total sales	5,867.9	3,772.9	4,880.2
North America | Kay
Disaggregation of Revenue [Line Items]
Total sales	2,985.8	2,008.6	2,414.0
North America | Zales
Disaggregation of Revenue [Line Items]
Total sales	1,624.8	1,121.6	1,276.8
North America | Jared
Disaggregation of Revenue [Line Items]
Total sales	1,326.3	920.9	1,088.1
North America | Banter by Piercing Pagoda
Disaggregation of Revenue [Line Items]
Total sales	553.4	337.5	331.7
North America | Diamonds Direct (2)
Disaggregation of Revenue [Line Items]
Total sales	132.5
North America | James Allen
Disaggregation of Revenue [Line Items]
Total sales	422.8	301.4	250.6
North America | Peoples
Disaggregation of Revenue [Line Items]
Total sales	206.2	150.9	204.6
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	13.0	0.0	0.0
North America | eCommerce
Disaggregation of Revenue [Line Items]
Total sales	1,396.9	1,068.0	685.6
North America | Other
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
International
Disaggregation of Revenue [Line Items]
Total sales	492.4	355.9	518.0
International | Bridal
Disaggregation of Revenue [Line Items]
Total sales	222.8	166.4	214.3
International | Fashion
Disaggregation of Revenue [Line Items]
Total sales	92.7	69.2	110.5
International | Watches
Disaggregation of Revenue [Line Items]
Total sales	157.8	108.5	169.1
International | Other
Disaggregation of Revenue [Line Items]
Total sales	19.1	11.8	24.1
International | Store
Disaggregation of Revenue [Line Items]
Total sales	377.7	238.9	453.2
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 | Banter by Piercing Pagoda
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
International | Diamonds Direct (2)
Disaggregation of Revenue [Line Items]
Total sales	0.0
International | James Allen
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	492.4	355.9	518.0
International | Other
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
International | eCommerce
Disaggregation of Revenue [Line Items]
Total sales	114.7	117.0	64.8
International | Other
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other
Disaggregation of Revenue [Line Items]
Total sales	68.8	30.1	53.3
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 | Other
Disaggregation of Revenue [Line Items]
Total sales	68.8	30.1	53.3
Other | Store
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
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 | Banter by Piercing Pagoda
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other | Diamonds Direct (2)
Disaggregation of Revenue [Line Items]
Total sales	0.0
Other | James Allen
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	68.8	30.1	53.3
Other | eCommerce
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0
Other | Other
Disaggregation of Revenue [Line Items]
Total sales	$ 68.8	$ 30.1	$ 53.3