Goodwill and intangibles - Composition of Intangible Assets and Liabilities (Details) - USD ($) $ in Millions	Jan. 30, 2021	Feb. 01, 2020
Intangible assets, net:
Definite-lived intangible assets, gross carrying amount	$ 53.6	$ 53.2
Definite-lived intangible assets, accumulated amortization	(52.2)	(50.9)
Net carrying amount	1.4	2.3
Indefinite-lived intangible assets	476.8	475.4
Indefinite-lived intangible assets, accumulated impairment loss	(299.2)	(213.9)
Indefinite-lived intangible assets, net	177.6	261.5
Intangible assets, gross	530.4	528.6
Total intangible assets, net	179.0	263.8
Definite-lived intangible liabilities:
Gross carrying amount	(114.2)	(113.9)
Accumulated amortization	103.7	98.0
Total	$ (10.5)	$ (15.9)