Revenue (Cumulative Effect of Adoption) (Details) - USD ($) $ in Millions	Jul. 31, 2019	Aug. 01, 2018	Jul. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Inventories, net	$ 332.8	$ 326.8	$ 334.1
Prepaid expenses and other current assets	82.5	66.3	52.3
Other current liabilities	73.1	86.9	86.6
Deferred income taxes	13.2	5.3	4.2
Non-controlling interest	1,281.5	1,127.4	$ 1,122.1
Calculated under Revenue Guidance in Effect before Topic 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Inventories, net	334.1
Prepaid expenses and other current assets	52.3
Other current liabilities	86.6
Deferred income taxes	4.2
Non-controlling interest	$ 1,122.1
Accounting Standards Update 2014-09 | Adjustments for ASC 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Inventories, net		(7.3)
Prepaid expenses and other current assets		14.0
Other current liabilities		0.3
Deferred income taxes		1.1
Non-controlling interest		$ 5.3