Financing Receivables and Operating Leases (Summary Of Allowances For Credit Loss And Related Financing Receivables) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 23, 2016	Jan. 24, 2015	Jan. 23, 2016	Jan. 24, 2015
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	$ 378	$ 368	$ 382	$ 349
Provisions	(9)	14	(5)	42
(Write-offs, net)	(1)	(1)	(8)	(4)
Foreign exchange and other	(3)	(6)	(4)	(12)
Allowance for credit loss as of	365	375	365	375
Lease Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	255	248	259	233
Provisions	(4)	7	(4)	29
(Write-offs, net)	0	(1)	(4)	(5)
Foreign exchange and other	(3)	(4)	(3)	(7)
Allowance for credit loss as of	248	250	248	250
Loan Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	90	84	87	98
Provisions	(10)	3	(6)	(10)
Recoveries, net	0	0	0	1
Foreign exchange and other	0	(2)	(1)	(4)
Allowance for credit loss as of	80	85	80	85
Financed Service Contracts and Other
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	33	36	36	18
Provisions	5	4	5	23
(Write-offs, net)	(1)	0	(4)	0
Foreign exchange and other	0	0	0	(1)
Allowance for credit loss as of	$ 37	$ 40	$ 37	$ 40