Financing Receivables and Operating Leases (Schedule of Financing Receivables Categorized by Internal Credit Risk Rating) (Details) - USD ($) $ in Millions	Jul. 29, 2017	Jul. 30, 2016
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	$ 9,716	$ 8,603
1 to 4
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	5,866	4,766
5 to 6
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	3,599	3,532
7 and Higher
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	251	305
Leases Receivables
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	2,639	3,098
Leases Receivables | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	1,408	1,703
Leases Receivables | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	1,181	1,294
Leases Receivables | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	50	101
Leases Receivables | Total
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	2,639	3,098
Loan Receivables | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	2,865	1,792
Loan Receivables | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	1,516	1,464
Loan Receivables | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	179	190
Loan Receivables | Total
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	4,560	3,446
Financed Service Contracts
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	2,517	2,059
Financed Service Contracts | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	1,593	1,271
Financed Service Contracts | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	902	774
Financed Service Contracts | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	22	14
Financed Service Contracts | Total
Financing Receivable, Recorded Investment [Line Items]
FInancing receivables net of unearned income	$ 2,517	$ 2,059