Financing Receivables and Operating Leases (Summary Of Allowances For Credit Loss And Related Financing Receivables) (Details) - USD ($) $ in Millions	3 Months Ended
	Oct. 29, 2016	Oct. 24, 2015
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	$ 375	$ 382
Provisions	8	4
Recoveries (write-offs), net		(7)
Foreign exchange and other	3	(1)
Allowance for credit loss as of	386	378
Lease Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	230	259
Provisions	(4)	0
Recoveries (write-offs), net		(4)
Foreign exchange and other	1	0
Allowance for credit loss as of	227	255
Loan Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	97	87
Provisions	12	4
Recoveries (write-offs), net		0
Foreign exchange and other	2	(1)
Allowance for credit loss as of	111	90
Financed Service Contracts and Other
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	48	36
Provisions	0	0
Recoveries (write-offs), net		(3)
Foreign exchange and other	0	0
Allowance for credit loss as of	$ 48	$ 33