Investments (Maturities Of Fixed Income Securities) (Details) (USD $) In Millions, unless otherwise specified	Oct. 25, 2014
Schedule of Investments [Line Items]
Amortized Cost	$ 45,775
Fair Value	45,923
Less than 1 year
Schedule of Investments [Line Items]
Amortized Cost	16,643
Fair Value	16,656
Due in 1 to 2 years
Schedule of Investments [Line Items]
Amortized Cost	14,222
Fair Value	14,270
Due in 2 to 5 years
Schedule of Investments [Line Items]
Amortized Cost	13,884
Fair Value	13,957
Due after 5 years
Schedule of Investments [Line Items]
Amortized Cost	1,026
Fair Value	$ 1,040