Balance Sheet Details (Details) - USD ($) $ in Millions	Apr. 27, 2019	Jul. 29, 2018	Jul. 28, 2018
Total cash, cash equivalents, and restricted cash
Cash and cash equivalents	$ 10,251		$ 8,934
Restricted cash included in other current assets	21		32
Restricted cash included in other assets	1		27
Total cash, cash equivalents, and restricted cash	10,273		8,993
Inventories:
Raw materials	398		423
Work in process	12		0
Finished goods:
Deferred cost of sales and distributor inventory	77		443
Manufactured finished goods	787		689
Total finished goods	864		1,132
Service-related spares	217		258
Demonstration systems	22		33
Total	1,513	$ 1,544	1,846
Gross property and equipment:
Land, buildings, and building and leasehold improvements	4,554		4,710
Computer equipment and related software	941		1,085
Production, engineering, and other equipment	5,688		5,734
Operating lease assets	562		356
Furniture and fixtures	370		358
Total gross property and equipment	12,115		12,243
Less: accumulated depreciation and amortization	(9,281)		(9,237)
Total	2,834		3,006
Disaggregation of Revenue [Line Items]
Deferred revenue:	17,456		19,685
Current	10,117	9,788	11,490
Noncurrent	7,339	$ 7,114	8,195
Service
Disaggregation of Revenue [Line Items]
Deferred revenue:	11,297		11,431
Product
Disaggregation of Revenue [Line Items]
Deferred revenue:	$ 6,159		$ 8,254