Investments (Maturities Of Fixed Income Securities) (Detail) (USD $) In Millions, unless otherwise specified	Oct. 26, 2013
Schedule of Investments [Line Items]
Fixed Income Securities, Amortized Cost	$ 40,334
Fixed Income Securities, Fair Value	40,433
Less than 1 year [Member]
Schedule of Investments [Line Items]
Fixed Income Securities, Amortized Cost	15,286
Fixed Income Securities, Fair Value	15,297
Fixed Income Securities Matures Between One And Two Years [Member]
Schedule of Investments [Line Items]
Fixed Income Securities, Amortized Cost	12,310
Fixed Income Securities, Fair Value	12,346
Fixed Income Securities Matures Between Two And Five Years [Member]
Schedule of Investments [Line Items]
Fixed Income Securities, Amortized Cost	12,160
Fixed Income Securities, Fair Value	12,204
Fixed Income Securities Matures Beyond Five Years [Member]
Schedule of Investments [Line Items]
Fixed Income Securities, Amortized Cost	578
Fixed Income Securities, Fair Value	$ 586