Goodwill and intangibles - Composition of Finite-Lived Intangibles (Details) - USD ($) $ in Millions	Aug. 04, 2018	Feb. 03, 2018	Jul. 29, 2017
Intangible assets, net:
Gross carrying amount	$ 53.4	$ 49.8	$ 49.8
Accumulated amortization	(48.6)	(46.7)	(43.6)
Net carrying amount	4.8	3.1	6.2
Accumulated amortization	(139.7)
Intangible assets, gross	529.6	528.2	457.5
Accumulated amortization, net	(48.6)	(46.7)	(43.6)
Total intangible assets, net	341.3	481.5	413.9
Definite-lived intangible liabilities:
Gross carrying amount	(114.0)	(114.5)	(114.5)
Accumulated amortization	88.8	85.2	80.5
Total	(25.2)	(29.3)	(34.0)
Trade names
Intangible assets, net:
Indefinite-lived intangible assets, gross	476.2	478.4	407.7
Accumulated amortization	(139.7)
Indefinite-lived intangible assets	$ 336.5	$ 478.4	$ 407.7

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Indefinite-Lived Intangible Assets, Accumulated Amortization

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