Fair Value (Fair Value On A Nonrecurring Basis) (Detail) (Fair Value, Inputs, Level 3 [Member], Investments In Privately Held Companies, USD $) In Millions, unless otherwise specified			3 Months Ended		6 Months Ended
	Jan. 25, 2014 Net Carrying Value	Jul. 27, 2013 Net Carrying Value	Jan. 25, 2014 Gains or Losses Included In Other Income (Loss), Net	Jan. 26, 2013 Gains or Losses Included In Other Income (Loss), Net	Jan. 25, 2014 Gains or Losses Included In Other Income (Loss), Net	Jan. 26, 2013 Gains or Losses Included In Other Income (Loss), Net
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Investment in privately held companies	$ 2	$ 60
Gains (Losses) for the Period			$ (9)	$ (8)	$ (10)	$ (18)