Quarterly Financial Information - Unaudited (Details) - USD ($) $ / shares in Units, $ 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
Quarterly Financial Information Disclosure [Abstract]
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
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
Net income	$ 178.8	$ (43.7)	$ (44.3)	$ (18.2)	$ (116.2)	$ (38.1)	$ (31.2)	$ (504.8)	$ 105.5	$ (657.4)	$ 519.3
Earnings (loss) per common share:
Earnings per share - basic (usd per share)	$ 3.45	$ (0.84)	$ (0.86)	$ (0.35)	$ (2.25)	$ (0.74)	$ (0.56)	$ (8.48)	$ 1.40	$ (12.62)	$ 7.72
Earnings per share - diluted (usd per share)	$ 3.14	$ (0.84)	$ (0.86)	$ (0.35)	$ (2.25)	$ (0.74)	$ (0.56)	$ (8.48)	$ 1.40	$ (12.62)	$ 7.44