Financing Receivables and Operating Leases (Summary Of Allowances For Credit Loss And Related Financing Receivables) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 29, 2017	Apr. 30, 2016	Apr. 29, 2017	Apr. 30, 2016
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of beginning of period	$ 378	$ 365	$ 375	$ 382
Provisions	(1)	17	8	12
Recoveries (write-offs), net	(9)	(6)	(15)	(14)
Foreign exchange and other	1	7	1	3
Allowance for credit loss as of end of period	369	383	369	383
Lease Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of beginning of period	225	248	230	259
Provisions	3	7	1	3
Recoveries (write-offs), net	(8)	(6)	(10)	(10)
Foreign exchange and other	0	1	(1)	(2)
Allowance for credit loss as of end of period	220	250	220	250
Loan Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of beginning of period	106	80	97	87
Provisions	10	8	22	2
Recoveries (write-offs), net	0	0	(4)	0
Foreign exchange and other	1	5	2	4
Allowance for credit loss as of end of period	117	93	117	93
Financed Service Contracts and Other
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of beginning of period	47	37	48	36
Provisions	(14)	2	(15)	7
Recoveries (write-offs), net	(1)	0	(1)	(4)
Foreign exchange and other	0	1	0	1
Allowance for credit loss as of end of period	$ 32	$ 40	$ 32	$ 40