Derivative Instruments (Additional Information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Oct. 25, 2014	Jul. 26, 2014
Derivative [Line Items]
Net derivative gains to be reclassified from AOCI into earnings in next twelve months	$ 52.3
Net liability position	99	67
Fixed Income Securities [Member]
Derivative [Line Items]
Number of Interest Rate Derivatives Held	0	0
Derivatives Designated As Cash Flow Hedges
Derivative [Line Items]
Foreign currency cash flow hedges maturity period, maximum, months	18 months
Net investment hedging instruments
Derivative [Line Items]
Foreign currency cash flow hedges maturity period, maximum, months	6 months
Right to request collateral subject to specified credit rating and in net liability position [Member]
Derivative [Line Items]
Net liability position	$ 0	$ 3