Balance Sheet Details (Details) - USD ($) $ in Millions	Jul. 28, 2018	Jul. 29, 2017	Jul. 30, 2016
Inventories:
Raw materials	$ 423	$ 289
Work in process	0	1
Finished goods:
Distributor inventory and deferred cost of sales	443	451
Manufactured finished goods	689	552
Total finished goods	1,132	1,003
Service-related spares	258	300
Demonstration systems	33	23
Total	1,846	1,616
Gross property and equipment:
Land, buildings, and building and leasehold improvements	4,710	4,926
Computer equipment and related software	1,085	1,258
Production, engineering, and other equipment	5,734	5,707
Operating lease assets	356	356
Furniture and fixtures	358	572
Total gross property and equipment	12,243	12,819
Less: accumulated depreciation and amortization	(9,237)	(9,497)
Total	3,006	3,322	$ 3,506
Deferred Revenue Arrangement [Line Items]
Deferred revenue:	19,685	18,494
Current	11,490	10,821
Noncurrent	8,195	7,673
Service
Deferred Revenue Arrangement [Line Items]
Deferred revenue:	11,431	11,302
Product:
Deferred Revenue Arrangement [Line Items]
Deferred revenue:	8,254	7,192
Product: | Deferred revenue related to recurring software and subscription offers
Deferred Revenue Arrangement [Line Items]
Deferred revenue:	6,120	4,971
Product: | Other product deferred revenue
Deferred Revenue Arrangement [Line Items]
Deferred revenue:	$ 2,134	$ 2,221