Condensed consolidating financial information - Condensed Consolidated Statement of Comprehensive Income (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 Statement of Comprehensive Income [Line Items]
Net income		$ 178.8	$ (43.7)	$ (44.3)	$ (18.2)	$ (116.2)	$ (38.1)	$ (31.2)	$ (504.8)	$ 105.5	$ (657.4)	$ 519.3
Other comprehensive income (loss):
Foreign currency translation adjustments										(1.7)	(35.9)	50.9
Available-for-sale securities:
Unrealized gain (loss)										(0.2)	0.4	0.3
Reclassification adjustment for (gains) losses to net income										1.0	0.0	0.0
Impact from adoption of new accounting pronouncements	[1]									0.0	(0.8)	0.0
Cash flow hedges:
Unrealized gain (loss)										11.2	4.8	1.8
Reclassification adjustment for losses to net income										(2.7)	(1.5)	(3.5)
Pension plan:
Actuarial gain (loss)										0.4	(3.4)	0.0
Reclassification adjustment to net income for amortization of actuarial losses										1.0	0.7	2.2
Prior service costs										0.0	(6.5)	(0.5)
Reclassification adjustment to net income for amortization of net prior service credits										0.0	0.0	(1.1)
Net curtailment gain and settlement loss										0.0	0.0	(3.0)
Total other comprehensive income (loss)										9.0	(42.2)	47.1
Total comprehensive income (loss)										114.5	(699.6)	566.4
Consolidation, Eliminations
Condensed Statement of Comprehensive Income [Line Items]
Net income										196.3	2,465.2	(983.8)
Other comprehensive income (loss):
Foreign currency translation adjustments										1.7	35.9	(50.9)
Available-for-sale securities:
Unrealized gain (loss)										0.2	(0.4)	(0.3)
Reclassification adjustment for (gains) losses to net income										(1.0)
Impact from adoption of new accounting pronouncements											0.8
Cash flow hedges:
Unrealized gain (loss)										(11.2)	(4.8)	(1.8)
Reclassification adjustment for losses to net income										2.7	1.5	3.5
Pension plan:
Actuarial gain (loss)										(0.4)	3.4
Reclassification adjustment to net income for amortization of actuarial losses										(1.0)	(0.7)	(2.2)
Prior service costs											6.5	0.5
Reclassification adjustment to net income for amortization of net prior service credits												1.1
Net curtailment gain and settlement loss												3.0
Total other comprehensive income (loss)										(9.0)	42.2	(47.1)
Total comprehensive income (loss)										187.3	2,507.4	(1,030.9)
Parent | Reportable Legal Entities
Condensed Statement of Comprehensive Income [Line Items]
Net income										105.5	(657.4)	519.3
Other comprehensive income (loss):
Foreign currency translation adjustments										(1.7)	(35.9)	50.9
Available-for-sale securities:
Unrealized gain (loss)										(0.2)	0.4	0.3
Reclassification adjustment for (gains) losses to net income										1.0
Impact from adoption of new accounting pronouncements											(0.8)
Cash flow hedges:
Unrealized gain (loss)										11.2	4.8	1.8
Reclassification adjustment for losses to net income										(2.7)	(1.5)	(3.5)
Pension plan:
Actuarial gain (loss)										0.4	(3.4)
Reclassification adjustment to net income for amortization of actuarial losses										1.0	0.7	2.2
Prior service costs											(6.5)	(0.5)
Reclassification adjustment to net income for amortization of net prior service credits												(1.1)
Net curtailment gain and settlement loss												(3.0)
Total other comprehensive income (loss)										9.0	(42.2)	47.1
Total comprehensive income (loss)										114.5	(699.6)	566.4
Issuer | Reportable Legal Entities
Condensed Statement of Comprehensive Income [Line Items]
Net income										6.1	3.2	(0.9)
Other comprehensive income (loss):
Foreign currency translation adjustments										0.0	0.0	0.0
Available-for-sale securities:
Unrealized gain (loss)										0.0	0.0	0.0
Reclassification adjustment for (gains) losses to net income										0.0
Impact from adoption of new accounting pronouncements											0.0
Cash flow hedges:
Unrealized gain (loss)										0.0	0.0	0.0
Reclassification adjustment for losses to net income										0.0	0.0	0.0
Pension plan:
Actuarial gain (loss)										0.0	0.0
Reclassification adjustment to net income for amortization of actuarial losses										0.0	0.0	0.0
Prior service costs											0.0	0.0
Reclassification adjustment to net income for amortization of net prior service credits												0.0
Net curtailment gain and settlement loss												0.0
Total other comprehensive income (loss)										0.0	0.0	0.0
Total comprehensive income (loss)										6.1	3.2	(0.9)
Guarantors | Reportable Legal Entities
Condensed Statement of Comprehensive Income [Line Items]
Net income										(320.7)	(1,770.0)	459.9
Other comprehensive income (loss):
Foreign currency translation adjustments										(1.7)	(35.4)	50.2
Available-for-sale securities:
Unrealized gain (loss)										0.0	0.0	0.0
Reclassification adjustment for (gains) losses to net income										0.0
Impact from adoption of new accounting pronouncements											0.0
Cash flow hedges:
Unrealized gain (loss)										11.2	4.8	1.8
Reclassification adjustment for losses to net income										(2.7)	(1.5)	(3.5)
Pension plan:
Actuarial gain (loss)										0.4	(3.4)
Reclassification adjustment to net income for amortization of actuarial losses										1.0	0.7	2.2
Prior service costs											(6.5)	(0.5)
Reclassification adjustment to net income for amortization of net prior service credits												(1.1)
Net curtailment gain and settlement loss												(3.0)
Total other comprehensive income (loss)										8.2	(41.3)	46.1
Total comprehensive income (loss)										(312.5)	(1,811.3)	506.0
Non-Guarantors | Reportable Legal Entities
Condensed Statement of Comprehensive Income [Line Items]
Net income										118.3	(698.4)	524.8
Other comprehensive income (loss):
Foreign currency translation adjustments											(0.5)	0.7
Available-for-sale securities:
Unrealized gain (loss)										(0.2)	0.4	0.3
Reclassification adjustment for (gains) losses to net income										1.0
Impact from adoption of new accounting pronouncements											(0.8)
Cash flow hedges:
Unrealized gain (loss)										0.0	0.0	0.0
Reclassification adjustment for losses to net income										0.0	0.0	0.0
Pension plan:
Actuarial gain (loss)										0.0	0.0
Reclassification adjustment to net income for amortization of actuarial losses										0.0	0.0	0.0
Prior service costs											0.0	0.0
Reclassification adjustment to net income for amortization of net prior service credits												0.0
Net curtailment gain and settlement loss												0.0
Total other comprehensive income (loss)										0.8	(0.9)	1.0
Total comprehensive income (loss)										$ 119.1	$ (699.3)	$ 525.8

[1] Adjustment reflects the reclassification of unrealized gains related to the Company’s available-for-sale equity securities as of February 3, 2018 from AOCI into retained earnings associated with the adoption of ASU 2016-01.