Leases (Supplemental Information) (Details) - USD ($) $ in Millions	Jul. 31, 2020	Aug. 01, 2019	Jul. 31, 2019
Leases [Abstract]
Right-of-use lease assets	$ 73.7	$ 71.5
Current lease liabilities	25.7	26.0
Long-term lease liabilities	$ 48.1	$ 45.5
Weighted average remaining lease term (years)	4 years 9 months 18 days		3 years 8 months 12 days
Weighted average discount rates (percentage)	3.52%		3.76%