Accumulated Other Comprehensive Income (Components Of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended
	Apr. 28, 2013		Apr. 29, 2012	Apr. 28, 2013		Apr. 29, 2012	Jul. 29, 2012
Total Accumulated other comprehensive loss	$ (709)			$ (709)			$ (776)
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax				7
Other Comprehensive Income Reclassifications Current Period Net of Tax				60
Other comprehensive income (loss), after tax	(9)		0	67		(58)
Accumulated Other Comprehensive Income Foreign Currency Translation Tax (Benefit) Expense	11			11			12
Accumulated Other Comprehensive Income Cashflow Hedges Tax (Benefit) Expense	(6)			(6)			(6)
Accumulated Other Comprehensive Income Unamortized Pension And Post Retirement Tax (Benefit) Expense	(549)			(549)			(581)
Accumulated Translation Adjustment [Member]
Total Accumulated other comprehensive loss	268	[1]		268	[1]		261	[1]
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax				7
Other comprehensive income (loss), after tax				7
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Total Accumulated other comprehensive loss	(10)	[2]		(10)	[2]		(10)	[2]
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax				(1)
Other Comprehensive Income Reclassifications Current Period Net of Tax				1
Other comprehensive income (loss), after tax				0
Accumulated Defined Benefit Plans Adjustment [Member]
Total Accumulated other comprehensive loss	(967)	[3]		(967)	[3]		(1,027)	[3]
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax				1
Other Comprehensive Income Reclassifications Current Period Net of Tax				59
Other comprehensive income (loss), after tax				$ 60

[1] Included a tax expense of $11 as of April 28, 2013, and $12 as of July 29, 2012. The amount related to noncontrolling interests was not material.

[2] Included a tax benefit of $6 as of April 28, 2013, and July 29, 2012.

[3] Included a tax benefit of $549 as of April 28, 2013, and $581 as of July 29, 2012.