Contingencies (Details) - Mentor Patent Litigation $ in Millions			3 Months Ended
	Oct. 10, 2014 USD ($)	Oct. 04, 2012 lawsuit patent	Jul. 31, 2018 USD ($)	Mar. 16, 2017 USD ($)
Loss Contingencies [Line Items]
Payments for legal settlements			$ 65.0
Release of loss contingency accrual			39.0
Litigation settlement expense			$ 26.0
Patent cross-license			7 years
Pending Litigation
Loss Contingencies [Line Items]
Loss contingency, patent infringement lawsuits | lawsuit		3
Loss contingency, patents allegedly infringed | patent		3
Loss contingency, value of damages sought	$ 36.0
Loss contingency, estimate of possible loss accrued				$ 39.0
Minimum
Loss Contingencies [Line Items]
Potential one-time termination charge			$ 0.0
Maximum
Loss Contingencies [Line Items]
Potential one-time termination charge			$ 25.0