Income Taxes (Schedule of Reconciliation of Beginning and Ending Amount of Gross Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Reconciliation of the Beginning and Ending Amounts of Gross Unrecognized Tax Benefits
Gross unrecognized tax benefits at beginning of fiscal year	$ 15.5	$ 18.5	$ 18.8
Additions for tax positions of the current fiscal year	2.8	2.5	4.4
Additions for tax positions of prior fiscal years	0.2	0.7	0.2
Reductions for tax positions of prior fiscal years	(0.1)	(4.9)	(3.1)
Settlements	0.0	0.0
Settlements			(0.4)
Reductions due to lapse of applicable statute of limitations	(1.5)	(1.3)	(1.4)
Gross unrecognized tax benefits at end of fiscal year	$ 16.9	$ 15.5	$ 18.5