Financing Receivables and Operating Leases - Summary of Allowances for Credit Loss and Related Financing Receivables (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 27, 2019	Jul. 28, 2018	Jul. 29, 2017
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit loss, beginning of period	$ 205	$ 295	$ 375
Provisions (benefits)	(16)	(89)	(35)
Recoveries (write-offs), net	(42)	(6)	(49)
Foreign exchange and other	(21)	5	4
Allowance for credit loss, end of period	126	205	295
Lease Receivables
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit loss, beginning of period	135	162	230
Provisions (benefits)	(54)	(26)	(25)
Recoveries (write-offs), net	(14)	(1)	(37)
Foreign exchange and other	(21)	0	(6)
Allowance for credit loss, end of period	46	135	162
Loan Receivables
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit loss, beginning of period	60	103	97
Provisions (benefits)	11	(43)	7
Recoveries (write-offs), net	0	(5)	(11)
Foreign exchange and other	0	5	10
Allowance for credit loss, end of period	71	60	103
Financed Service Contracts
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit loss, beginning of period	10	30	48
Provisions (benefits)	27	(20)	(17)
Recoveries (write-offs), net	(28)	0	(1)
Foreign exchange and other	0	0	0
Allowance for credit loss, end of period	$ 9	$ 10	$ 30