Fair Value (Assets and Liabilities Measured At Fair Value On Recurring Basis) (Details) - USD ($) $ in Millions	Oct. 24, 2015	Jul. 25, 2015
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	$ 58,034	$ 59,107
Cash equivalents: | Money market funds
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	4,317	5,336
Cash equivalents: | Corporate debt securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	25	14
Available-for-sale investments: | U.S. government securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	27,471	29,939
Available-for-sale investments: | U.S. government agency securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	3,617	3,663
Available-for-sale investments: | Non-U.S. government and agency securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	1,136	1,128
Available-for-sale investments: | Corporate debt securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	18,306	15,783
Available-for-sale investments: | U.S. agency mortgage-backed securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	1,469	1,461
Available-for-sale investments: | Publicly traded equity securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	1,350	1,565
Derivative assets
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	343	218
Derivative liabilities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities:	14	12
Level 1
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	5,667	6,901
Level 1 | Cash equivalents: | Money market funds
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	4,317	5,336
Level 1 | Cash equivalents: | Corporate debt securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 1 | Available-for-sale investments: | U.S. government securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 1 | Available-for-sale investments: | U.S. government agency securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 1 | Available-for-sale investments: | Non-U.S. government and agency securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 1 | Available-for-sale investments: | Corporate debt securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 1 | Available-for-sale investments: | U.S. agency mortgage-backed securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 1 | Available-for-sale investments: | Publicly traded equity securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	1,350	1,565
Level 1 | Derivative assets
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 1 | Derivative liabilities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities:	0	0
Level 2
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	52,364	52,202
Level 2 | Cash equivalents: | Money market funds
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 2 | Cash equivalents: | Corporate debt securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	25	14
Level 2 | Available-for-sale investments: | U.S. government securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	27,471	29,939
Level 2 | Available-for-sale investments: | U.S. government agency securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	3,617	3,663
Level 2 | Available-for-sale investments: | Non-U.S. government and agency securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	1,136	1,128
Level 2 | Available-for-sale investments: | Corporate debt securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	18,306	15,783
Level 2 | Available-for-sale investments: | U.S. agency mortgage-backed securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	1,469	1,461
Level 2 | Available-for-sale investments: | Publicly traded equity securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 2 | Derivative assets
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	340	214
Level 2 | Derivative liabilities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities:	14	12
Level 3
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	3	4
Level 3 | Cash equivalents: | Money market funds
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 3 | Cash equivalents: | Corporate debt securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 3 | Available-for-sale investments: | U.S. government securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 3 | Available-for-sale investments: | U.S. government agency securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 3 | Available-for-sale investments: | Non-U.S. government and agency securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 3 | Available-for-sale investments: | Corporate debt securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 3 | Available-for-sale investments: | U.S. agency mortgage-backed securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 3 | Available-for-sale investments: | Publicly traded equity securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	0	0
Level 3 | Derivative assets
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets:	3	4
Level 3 | Derivative liabilities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities:	$ 0	$ 0