Segment Information - Summary of Activity by Segment (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jan. 28, 2017	Oct. 29, 2016	Jul. 30, 2016	Apr. 30, 2016	Jan. 30, 2016	Oct. 31, 2015	Aug. 01, 2015	May 02, 2015	Jan. 28, 2017	Jan. 30, 2016	Jan. 31, 2015
Segment Reporting Information [Line Items]
Sales	$ 2,269.9	$ 1,186.2	$ 1,373.4	$ 1,578.9	$ 2,392.6	$ 1,216.4	$ 1,410.6	$ 1,530.6	$ 6,408.4	$ 6,550.2	$ 5,736.3
Operating income (loss)									763.2	703.7	576.6
Depreciation and amortization									188.8	175.3	149.7
Capital additions									278.0	226.5	220.2
Total assets	6,597.8				6,464.9				6,597.8	6,464.9
Total long-lived assets	1,757.5				1,670.9				1,757.5	1,670.9
Total liabilities	3,495.7				3,404.2				3,495.7	3,404.2
Sterling Jewelers
Segment Reporting Information [Line Items]
Sales									3,930.4	3,988.7	3,765.0
Operating income (loss)									715.8	718.6	624.3
Depreciation and amortization									112.7	106.2	95.7
Capital additions									154.5	141.6	157.6
Total assets	4,015.4				3,788.0				4,015.4	3,788.0
Total long-lived assets	567.3				519.7				567.3	519.7
Total liabilities	2,061.4				1,982.2				2,061.4	1,982.2
Zale Jewelry
Segment Reporting Information [Line Items]
Sales									1,549.7	1,568.2	1,068.7
Operating income (loss)									62.2	44.3	(1.9)
Depreciation and amortization									49.1	44.8	29.4
Capital additions									85.0	47.7	35.1
Impact of purchase accounting adjustments on operating income loss									(16.4)	(23.1)	35.1
Total assets	1,940.7				1,955.1				1,940.7	1,955.1
Total long-lived assets	1,050.1				1,013.7				1,050.1	1,013.7
Total liabilities	524.3				530.3				524.3	530.3
Zale Jewelry | Canada
Segment Reporting Information [Line Items]
Sales									234.6	248.7	205.5
Piercing Pagoda
Segment Reporting Information [Line Items]
Sales									263.1	243.2	146.9
Operating income (loss)									11.2	7.8	(6.3)
Depreciation and amortization									4.6	3.3	1.6
Capital additions									12.7	10.2	6.9
Impact of purchase accounting adjustments on operating income loss									(0.4)	(3.3)	10.8
Total assets	141.6				141.8				141.6	141.8
Total long-lived assets	61.4				53.3				61.4	53.3
Total liabilities	28.2				28.5				28.2	28.5
UK Jewelry
Segment Reporting Information [Line Items]
Sales									647.1	737.6	743.6
Operating income (loss)									45.6	61.5	52.2
Depreciation and amortization									21.6	20.1	22.1
Capital additions									25.7	26.4	20.2
Total assets	372.6				427.8				372.6	427.8
Total long-lived assets	70.7				75.3				70.7	75.3
Total liabilities	110.6				132.0				110.6	132.0
Other
Segment Reporting Information [Line Items]
Sales									18.1	12.5	12.1
Operating income (loss)									(71.6)	(128.5)	(91.7)
Depreciation and amortization									0.8	0.9	0.9
Capital additions									0.1	0.6	0.4
Acquisition integration and severance related costs									28.4	78.9	59.8
Total assets	127.5				152.2				127.5	152.2
Total long-lived assets	8.0				8.9				8.0	8.9
Total liabilities	$ 771.2				$ 731.2				771.2	731.2
Diamonds and diamond jewelry
Segment Reporting Information [Line Items]
Sales									3,853.7	3,918.1	3,450.6
Gold, silver jewelry, other products and services
Segment Reporting Information [Line Items]
Sales									2,090.0	2,116.4	1,784.5
Watches
Segment Reporting Information [Line Items]
Sales									$ 464.7	$ 515.7	$ 501.2