Financing Receivables - Schedule of Financing Receivables (Details) - USD ($) $ in Millions	Oct. 30, 2021	Jul. 31, 2021	Oct. 24, 2020	Jul. 25, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross	$ 8,698	$ 9,366
Residual value	97	103
Unearned income	(70)	(78)
Allowance for credit loss	(109)	(127)	$ (154)	$ (138)
Total, net	8,616	9,264
Current	4,070	4,380
Noncurrent	4,546	4,884
Lease Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross	1,560	1,710
Residual value	97	103
Unearned income	(70)	(78)
Allowance for credit loss	(33)	(38)	(46)	(48)
Total, net	1,554	1,697
Current	736	780
Noncurrent	818	917
Loan Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross	4,809	5,203
Unearned income	0	0
Allowance for credit loss	(74)	(86)	(101)	(81)
Total, net	4,735	5,117
Current	2,198	2,372
Noncurrent	2,537	2,745
Financed Service Contracts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross	2,329	2,453
Unearned income	0	0
Allowance for credit loss	(2)	(3)	$ (7)	$ (9)
Total, net	2,327	2,450
Current	1,136	1,228
Noncurrent	$ 1,191	$ 1,222