Leases (Lease liabilities) (Details) - USD ($) $ in Millions		May 02, 2020		Aug. 03, 2019
Leases [Abstract]
Weighted-average remaining lease term (years)		5 years 3 months 18 days
Weighted-average discount rate (percent)		25.70%
Lease Maturity, Current [Abstract]
2020 (excluding the nine months ended May 2, 2020)	[1],[2]	$ 99.5
2021	[1],[2]	355.1
2022	[1],[2]	290.5
2023	[1],[2]	213.4
2024	[1],[2]	148.9
Thereafter	[1],[2]	462.6
Total undiscounted operating lease liabilities	[1],[2]	1,570.0
Less imputed interest	[1],[2]	(733.0)
Present value of operating lease liabilities	[1],[2]	837.0
Less current portion of lease liabilities		(167.7)	[1],[2]	$ 0.0
Long-term lease liabilities		$ 669.3	[1],[2]	0.0
Lease Maturity, Prior
2020	[3],[4]			462.0
2021	[3],[4]			402.3
2022	[3],[4]			325.4
2023	[3],[4]			242.7
2024	[3],[4]			172.6
Thereafter	[3],[4]			563.3
Total undiscounted operating lease liabilities	[3],[4]			$ 2,168.3

[1] Although such amounts are generally non-cancelable, certain leases are cancelable if specified sales levels are not achieved or co-tenancy requirements are not being satisfied. All future minimum rentals under such leases have been included in the above table.

[2] Net of sublease income, which is not expected to be significant in any period.

[3] Although such amounts are generally non-cancelable, certain leases are cancelable if specified sales levels are not achieved or co-tenancy requirements are not being satisfied. All future minimum rentals under such leases have been included in the above table.

[4] Net of sublease income, which is not expected to be significant in any period.