Revenue recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Aug. 01, 2026	Aug. 02, 2025	Aug. 01, 2026	Aug. 02, 2025
Disaggregation of Revenue [Line Items]
Total sales	$ 1,528.1	$ 1,535.1	$ 3,081.7	$ 3,076.7
Bridal
Disaggregation of Revenue [Line Items]
Total sales	662.6	666.0	1,350.9	1,351.3
Fashion
Disaggregation of Revenue [Line Items]
Total sales	535.5	550.3	1,094.7	1,106.4
Watches
Disaggregation of Revenue [Line Items]
Total sales	89.3	80.7	164.7	150.2
Service sales
Disaggregation of Revenue [Line Items]
Total sales	199.2	192.3	400.4	383.6
Other
Disaggregation of Revenue [Line Items]
Total sales	41.5	45.8	71.0	85.2
Kay
Disaggregation of Revenue [Line Items]
Total sales	585.2	569.5	1,183.6	1,148.6
Zales
Disaggregation of Revenue [Line Items]
Total sales	275.1	270.0	564.2	553.2
Jared
Disaggregation of Revenue [Line Items]
Total sales	262.1	262.2	522.4	522.2
Blue Nile
Disaggregation of Revenue [Line Items]
Total sales	83.6	74.7	158.4	152.3
James Allen
Disaggregation of Revenue [Line Items]
Total sales	7.1	36.9	31.2	76.3
Diamonds Direct
Disaggregation of Revenue [Line Items]
Total sales	88.0	87.1	173.0	171.2
Banter by Piercing Pagoda
Disaggregation of Revenue [Line Items]
Total sales	70.2	75.6	151.7	157.8
Peoples
Disaggregation of Revenue [Line Items]
Total sales	47.8	47.8	95.4	88.6
International segment
Disaggregation of Revenue [Line Items]
Total sales	96.6	91.8	184.1	171.9
Other
Disaggregation of Revenue [Line Items]
Total sales	12.4	19.5	17.7	34.6
Store
Disaggregation of Revenue [Line Items]
Total sales	1,216.5	1,198.3	2,443.2	2,386.4
E-commerce
Disaggregation of Revenue [Line Items]
Total sales	300.0	317.6	622.1	656.3
Other
Disaggregation of Revenue [Line Items]
Total sales	11.6	19.2	16.4	34.0
North America
Disaggregation of Revenue [Line Items]
Total sales	1,428.3	1,426.7	2,891.3	2,877.2
North America \| Bridal
Disaggregation of Revenue [Line Items]
Total sales	628.9	633.0	1,285.5	1,289.6
North America \| Fashion
Disaggregation of Revenue [Line Items]
Total sales	507.6	523.9	1,040.4	1,056.9
North America \| Watches
Disaggregation of Revenue [Line Items]
Total sales	62.6	55.5	115.9	103.3
North America \| Service sales
Disaggregation of Revenue [Line Items]
Total sales	192.5	185.9	387.4	371.3
North America \| Other
Disaggregation of Revenue [Line Items]
Total sales	36.7	28.4	62.1	56.1
North America \| Kay
Disaggregation of Revenue [Line Items]
Total sales	585.2	569.5	1,183.6	1,148.6
North America \| Zales
Disaggregation of Revenue [Line Items]
Total sales	275.1	270.0	564.2	553.2
North America \| Jared
Disaggregation of Revenue [Line Items]
Total sales	262.1	262.2	522.4	522.2
North America \| Blue Nile
Disaggregation of Revenue [Line Items]
Total sales	83.6	74.7	158.4	152.3
North America \| James Allen
Disaggregation of Revenue [Line Items]
Total sales	7.1	36.9	31.2	76.3
North America \| Diamonds Direct
Disaggregation of Revenue [Line Items]
Total sales	88.0	87.1	173.0	171.2
North America \| Banter by Piercing Pagoda
Disaggregation of Revenue [Line Items]
Total sales	70.2	75.6	151.7	157.8
North America \| Peoples
Disaggregation of Revenue [Line Items]
Total sales	47.8	47.8	95.4	88.6
North America \| International segment
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
North America \| Other
Disaggregation of Revenue [Line Items]
Total sales	9.2	2.9	11.4	7.0
North America \| Store
Disaggregation of Revenue [Line Items]
Total sales	1,140.1	1,125.6	2,296.4	2,250.9
North America \| E-commerce
Disaggregation of Revenue [Line Items]
Total sales	279.8	298.5	584.8	619.9
North America \| Other
Disaggregation of Revenue [Line Items]
Total sales	8.4	2.6	10.1	6.4
International segment
Disaggregation of Revenue [Line Items]
Total sales	96.6	91.8	184.1	171.9
International segment \| Bridal
Disaggregation of Revenue [Line Items]
Total sales	33.7	33.0	65.4	61.7
International segment \| Fashion
Disaggregation of Revenue [Line Items]
Total sales	27.9	26.4	54.3	49.5
International segment \| Watches
Disaggregation of Revenue [Line Items]
Total sales	26.7	25.2	48.8	46.9
International segment \| Service sales
Disaggregation of Revenue [Line Items]
Total sales	6.7	6.4	13.0	12.3
International segment \| Other
Disaggregation of Revenue [Line Items]
Total sales	1.6	0.8	2.6	1.5
International segment \| Kay
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
International segment \| Zales
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
International segment \| Jared
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
International segment \| Blue Nile
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
International segment \| James Allen
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
International segment \| Diamonds Direct
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
International segment \| Banter by Piercing Pagoda
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
International segment \| Peoples
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
International segment \| International segment
Disaggregation of Revenue [Line Items]
Total sales	96.6	91.8	184.1	171.9
International segment \| Other
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
International segment \| Store
Disaggregation of Revenue [Line Items]
Total sales	76.4	72.7	146.8	135.5
International segment \| E-commerce
Disaggregation of Revenue [Line Items]
Total sales	20.2	19.1	37.3	36.4
International segment \| Other
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
Other
Disaggregation of Revenue [Line Items]
Total sales	3.2	16.6	6.3	27.6
Other \| Bridal
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
Other \| Fashion
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
Other \| Watches
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
Other \| Service sales
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
Other \| Other
Disaggregation of Revenue [Line Items]
Total sales	3.2	16.6	6.3	27.6
Other \| Kay
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
Other \| Zales
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
Other \| Jared
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
Other \| Blue Nile
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
Other \| James Allen
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
Other \| Diamonds Direct
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
Other \| Banter by Piercing Pagoda
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
Other \| Peoples
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
Other \| International segment
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
Other \| Other
Disaggregation of Revenue [Line Items]
Total sales	3.2	16.6	6.3	27.6
Other \| Store
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
Other \| E-commerce
Disaggregation of Revenue [Line Items]
Total sales	0.0	0.0	0.0	0.0
Other \| Other
Disaggregation of Revenue [Line Items]
Total sales	$ 3.2	$ 16.6	$ 6.3	$ 27.6