Financing Receivables - Summary of Allowances for Credit Loss and Related Financing Receivables (Details) - USD ($) $ in Millions	3 Months Ended
	Oct. 24, 2020	Oct. 26, 2019
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit loss as of beginning of period	$ 138	$ 126
Provisions (benefits)	(1)	24
Recoveries (write-offs), net		(16)
Foreign exchange and other	17	(1)
Allowance for credit loss as of end of period	154	133
Lease Receivables
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit loss as of beginning of period	48	46
Provisions (benefits)	(3)	(3)
Recoveries (write-offs), net		0
Foreign exchange and other	1	0
Allowance for credit loss as of end of period	46	43
Loan Receivables
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit loss as of beginning of period	81	71
Provisions (benefits)	3	27
Recoveries (write-offs), net		(16)
Foreign exchange and other	17	(1)
Allowance for credit loss as of end of period	101	81
Financed Service Contracts
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit loss as of beginning of period	9	9
Provisions (benefits)	(1)	0
Recoveries (write-offs), net		0
Foreign exchange and other	(1)	0
Allowance for credit loss as of end of period	$ 7	$ 9