Balance Sheet Details (Details) - USD ($) $ in Millions	Jan. 27, 2018	Jul. 29, 2017
Inventories:
Raw materials	$ 385	$ 289
Work in Process	0	1
Finished goods:
Distributor inventory and deferred cost of sales	465	451
Manufactured finished goods	727	552
Total finished goods	1,192	1,003
Service-related spares	292	300
Demonstration systems	27	23
Total	1,896	1,616
Gross property and equipment:
Land, buildings, and building and leasehold improvements	4,790	4,926
Computer equipment and related software	1,207	1,258
Production, engineering, and other equipment	5,702	5,707
Operating lease assets	364	356
Furniture and fixtures	375	572
Total gross property and equipment	12,438	12,819
Less: accumulated depreciation and amortization	(9,325)	(9,497)
Total	3,113	3,322
Deferred Revenue Arrangement [Line Items]
Deferred revenue:	18,788	18,494
Current	11,102	10,821
Noncurrent	7,686	7,673
Product:
Deferred Revenue Arrangement [Line Items]
Deferred revenue:	7,825	7,192
Service
Deferred Revenue Arrangement [Line Items]
Deferred revenue:	10,963	11,302
Deferred revenue related to recurring software and subscription offers | Product:
Deferred Revenue Arrangement [Line Items]
Deferred revenue:	5,451	4,971
Other product deferred revenue | Product:
Deferred Revenue Arrangement [Line Items]
Deferred revenue:	$ 2,374	$ 2,221