Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended		12 Months Ended
	Jan. 31, 2019	Jul. 31, 2018	Jan. 31, 2018	Jan. 31, 2019	Jan. 31, 2018	Jul. 31, 2018
Tax benefits recognized provided percentage of likelihood of realization is more than				50.00%
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	$ 4.8		$ 2.6	$ 5.0	$ 6.4
Gross unrecognized tax benefit	30.4			$ 30.4
Other Tax Expense Benefit Transition Tax Net of Foreign Tax Credit	$ 1.1	$ 12.4
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	20.40%		28.50%	21.80%	30.10%	26.90%
Domestic Tax Authority [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%		35.00%			10.50%