Discontinued Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Aug. 03, 2014	Apr. 27, 2014	Jan. 26, 2014	Oct. 27, 2013	Jul. 28, 2013	Apr. 28, 2013	Jan. 27, 2013	Oct. 28, 2012	Aug. 03, 2014	Jul. 28, 2013	Jul. 29, 2012	Jul. 31, 2011
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Earnings (loss) from discontinued operations	$ 0	$ 0	$ 90	$ (9)	$ (275)	$ 12	$ 19	$ 13	$ 81	$ (231)	$ 40
Cash					68					68	0	0
Current assets of discontinued operations held for sale	0				193				0	193
Non-current assets of discontinued operations held for sale	0				393				0	393
Current liabilties of discontinued operations held for sale	0				114				0	114
Non-current liabilities of discontinued operations held for sale	0				22				0	22
Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales									137	532	532
Gain on sale of business									141	0	0
Impairment of long-lived assets to be disposed of									0	(396)	0
Earnings from discontinued operations, before tax									14	65	57
Earnings before taxes									155	(331)	57
Taxes on earnings									(74)	100	(17)
Earnings (loss) from discontinued operations									81	(231)	40
Cash					68					68
Accounts receivable					54					54
Inventories					68					68
Prepaid expense					3					3
Current assets of discontinued operations held for sale					193					193
Plant assets					98					98
Goodwill					110					110
Intangible assets					150					150
Other assets					35					35
Non-current assets of discontinued operations held for sale					393					393
Accounts payable					60					60
Accrued liabilities					54					54
Current liabilties of discontinued operations held for sale					114					114
Non-current pension obligation					11					11
Other liabilities					11					11
Non-current liabilities of discontinued operations held for sale					$ 22					$ 22