Investments (Maturities Of Fixed Income Securities) (Detail) (USD $) In Millions, unless otherwise specified	Apr. 26, 2014
Schedule of Investments [Line Items]
Fixed Income Securities, Amortized Cost	$ 42,171
Fixed Income Securities, Fair Value	42,269
Less than 1 year [Member]
Schedule of Investments [Line Items]
Fixed Income Securities, Amortized Cost	15,022
Fixed Income Securities, Fair Value	15,038
Fixed Income Securities Matures Between One And Two Years [Member]
Schedule of Investments [Line Items]
Fixed Income Securities, Amortized Cost	13,061
Fixed Income Securities, Fair Value	13,101
Fixed Income Securities Matures Between Two And Five Years [Member]
Schedule of Investments [Line Items]
Fixed Income Securities, Amortized Cost	13,380
Fixed Income Securities, Fair Value	13,415
Fixed Income Securities Matures Beyond Five Years [Member]
Schedule of Investments [Line Items]
Fixed Income Securities, Amortized Cost	708
Fixed Income Securities, Fair Value	$ 715