Investments (Summary Of Available-For-Sale Investments) (Details) (USD $) In Millions, unless otherwise specified	Apr. 25, 2015	Jul. 26, 2014
Available-for-sale investments: [Line Items]
Amortized Cost	$ 49,800	$ 44,619
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	767	759
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(18)	(30)
Fair Value	50,549us-gaap_AvailableForSaleSecurities	45,348us-gaap_AvailableForSaleSecurities
Total fixed income securities
Available-for-sale investments: [Line Items]
Amortized Cost	48,472	43,305
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	169	111
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(15)	(20)
Fair Value	48,626	43,396
Total fixed income securities \| U.S. government securities
Available-for-sale investments: [Line Items]
Amortized Cost	29,364	31,717
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	59	29
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(1)	(12)
Fair Value	29,422	31,734
Total fixed income securities \| U.S. government agency securities
Available-for-sale investments: [Line Items]
Amortized Cost	3,257	1,062
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	6	1
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(1)	0
Fair Value	3,262	1,063
Total fixed income securities \| Non-U.S. government and agency securities
Available-for-sale investments: [Line Items]
Amortized Cost	1,184	860
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	2	2
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	0	(1)
Fair Value	1,186	861
Total fixed income securities \| Corporate debt securities
Available-for-sale investments: [Line Items]
Amortized Cost	13,321	9,092
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	86	74
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(13)	(7)
Fair Value	13,394	9,159
Total fixed income securities \| U.S. agency mortgage-backed securities
Available-for-sale investments: [Line Items]
Amortized Cost	1,346	574
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	16	5
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	0	0
Fair Value	1,362	579
Publicly traded equity securities [Member]
Available-for-sale investments: [Line Items]
Amortized Cost	1,328	1,314
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	598	648
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(3)	(10)
Fair Value	$ 1,923	$ 1,952

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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-Publisher FASB

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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