Condensed consolidating financial information - Condensed Consolidated Statement of Operations (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Feb. 01, 2020	Nov. 02, 2019	Aug. 03, 2019	May 04, 2019	Feb. 02, 2019	Nov. 03, 2018	Aug. 04, 2018	May 05, 2018	Feb. 01, 2020	Feb. 02, 2019	Feb. 03, 2018
Condensed Income Statements, Captions [Line Items]
Total sales	$ 2,153.3	$ 1,187.7	$ 1,364.4	$ 1,431.7	$ 2,154.7	$ 1,191.7	$ 1,420.1	$ 1,480.6	$ 6,137.1	$ 6,247.1	$ 6,253.0
Cost of sales									(3,904.2)	(4,024.1)	(4,063.0)
Restructuring charges - cost of sales									(9.2)	(62.2)	0.0
Gross margin	897.9	367.7	458.7	499.4	877.8	371.2	427.0	484.8	2,223.7	2,160.8	2,190.0
Selling, general and administrative expenses									(1,918.2)	(1,985.1)	(1,872.2)
Restructuring charges									(69.9)	(63.7)	0.0
Credit transaction, net									0.0	(167.4)	1.3
Restructuring charges									(25.9)	(84.9)	0.0
Goodwill and intangible impairments					(286.7)				(47.7)	(735.4)	0.0
Other operating income (loss), net									(29.6)	26.2	260.8
Operating income (loss)									158.3	(764.6)	579.9
Intra-entity interest income (expense)									0.0	0.0
Interest expense, net									(35.6)	(39.7)	(52.7)
Other non-operating income, net									7.0	1.7	0.0
Income (loss) before income taxes									129.7	(802.6)	527.2
Income taxes									(24.2)	145.2	(7.9)
Equity in income of subsidiaries									0.0	0.0
Net income (loss)	$ 178.8	$ (43.7)	$ (44.3)	$ (18.2)	$ (116.2)	$ (38.1)	$ (31.2)	$ (504.8)	105.5	(657.4)	519.3
Dividends on redeemable convertible preferred shares									(32.9)	(32.9)	(32.9)
Net income (loss) attributable to common shareholders									72.6	(690.3)	486.4
Consolidation, Eliminations
Condensed Income Statements, Captions [Line Items]
Total sales									0.0	0.0	0.0
Cost of sales									0.0	0.0	0.0
Restructuring charges - cost of sales									0.0	0.0
Gross margin									0.0	0.0	0.0
Selling, general and administrative expenses									0.0	0.0	0.0
Restructuring charges									0.0	0.0
Credit transaction, net										0.0	0.0
Goodwill and intangible impairments									0.0	0.0
Other operating income (loss), net									0.0	0.0	0.0
Operating income (loss)									0.0	0.0	0.0
Intra-entity interest income (expense)									0.0	0.0	0.0
Interest expense, net									0.0	0.0	0.0
Other non-operating income, net									0.0	0.0
Income (loss) before income taxes									0.0	0.0	0.0
Income taxes									0.0	0.0	0.0
Equity in income of subsidiaries									196.3	2,465.2	(983.8)
Net income (loss)									196.3	2,465.2	(983.8)
Dividends on redeemable convertible preferred shares									0.0	0.0	0.0
Net income (loss) attributable to common shareholders									196.3	2,465.2	(983.8)
Parent
Condensed Income Statements, Captions [Line Items]
Dividends on redeemable convertible preferred shares									(32.9)	(32.9)	(32.9)
Parent | Reportable Legal Entities
Condensed Income Statements, Captions [Line Items]
Total sales									0.0	0.0	0.0
Cost of sales									0.0	0.0	0.0
Restructuring charges - cost of sales									0.0	0.0
Gross margin									0.0	0.0	0.0
Selling, general and administrative expenses									(0.9)	(1.0)	(1.9)
Restructuring charges									0.0	0.0
Credit transaction, net										0.0	0.0
Goodwill and intangible impairments									0.0	0.0
Other operating income (loss), net									0.0	(0.1)	0.1
Operating income (loss)									(0.9)	(1.1)	(1.8)
Intra-entity interest income (expense)									(2.2)	(4.6)	0.0
Interest expense, net									0.0	0.0	0.0
Other non-operating income, net									0.0	0.0
Income (loss) before income taxes									(3.1)	(5.7)	(1.8)
Income taxes									0.0	0.0	0.0
Equity in income of subsidiaries									108.6	(651.7)	521.1
Net income (loss)									105.5	(657.4)	519.3
Net income (loss) attributable to common shareholders									72.6	(690.3)	486.4
Issuer | Reportable Legal Entities
Condensed Income Statements, Captions [Line Items]
Total sales									0.0	0.0	0.0
Cost of sales									0.0	0.0	0.0
Restructuring charges - cost of sales									0.0	0.0
Gross margin									0.0	0.0	0.0
Selling, general and administrative expenses									0.0	0.0	0.0
Restructuring charges									0.0	0.0
Credit transaction, net										0.0	0.0
Goodwill and intangible impairments									0.0	0.0
Other operating income (loss), net									0.0	0.0	0.0
Operating income (loss)									0.0	0.0	0.0
Intra-entity interest income (expense)									14.9	18.9	18.8
Interest expense, net									(15.5)	(14.9)	(19.9)
Other non-operating income, net									8.1	0.0
Income (loss) before income taxes									7.5	4.0	(1.1)
Income taxes									(1.4)	(0.8)	0.2
Equity in income of subsidiaries									0.0	0.0	0.0
Net income (loss)									6.1	3.2	(0.9)
Dividends on redeemable convertible preferred shares									0.0	0.0	0.0
Net income (loss) attributable to common shareholders									6.1	3.2	(0.9)
Guarantors | Reportable Legal Entities
Condensed Income Statements, Captions [Line Items]
Total sales									5,656.3	5,722.8	5,866.6
Cost of sales									(3,589.1)	(3,755.5)	(3,926.6)
Restructuring charges - cost of sales									(6.0)	(56.5)
Gross margin									2,061.2	1,910.8	1,940.0
Selling, general and administrative expenses									(1,872.2)	(1,833.4)	(1,738.2)
Restructuring charges									(62.9)	(55.3)
Credit transaction, net										(167.4)	1.3
Goodwill and intangible impairments									(35.2)	(470.4)
Other operating income (loss), net									(29.3)	22.5	260.3
Operating income (loss)									61.6	(593.2)	463.4
Intra-entity interest income (expense)									(176.8)	(243.4)	(190.2)
Interest expense, net									(20.3)	(25.0)	(21.6)
Other non-operating income, net									(1.1)	1.7
Income (loss) before income taxes									(136.6)	(859.9)	251.6
Income taxes									(20.0)	133.0	(21.3)
Equity in income of subsidiaries									(164.1)	(1,043.1)	229.6
Net income (loss)									(320.7)	(1,770.0)	459.9
Dividends on redeemable convertible preferred shares									0.0	0.0	0.0
Net income (loss) attributable to common shareholders									(320.7)	(1,770.0)	459.9
Non-Guarantors | Reportable Legal Entities
Condensed Income Statements, Captions [Line Items]
Total sales									480.8	524.3	386.4
Cost of sales									(315.1)	(268.6)	(136.4)
Restructuring charges - cost of sales									(3.2)	(5.7)
Gross margin									162.5	250.0	250.0
Selling, general and administrative expenses									(45.1)	(150.7)	(132.1)
Restructuring charges									(7.0)	(8.4)
Credit transaction, net										0.0	0.0
Goodwill and intangible impairments									(12.5)	(265.0)
Other operating income (loss), net									(0.3)	3.8	0.4
Operating income (loss)									97.6	(170.3)	118.3
Intra-entity interest income (expense)									164.1	229.1	171.4
Interest expense, net									0.2	0.2	(11.2)
Other non-operating income, net									0.0	0.0
Income (loss) before income taxes									261.9	59.0	278.5
Income taxes									(2.8)	13.0	13.2
Equity in income of subsidiaries									(140.8)	(770.4)	233.1
Net income (loss)									118.3	(698.4)	524.8
Dividends on redeemable convertible preferred shares									0.0	0.0	0.0
Net income (loss) attributable to common shareholders									$ 118.3	$ (698.4)	$ 524.8