Investments, Marketable Securities, Credit Losses on and Maturities of Debt Securities (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Apr. 27, 2012	Apr. 29, 2011
Short-term
Available-for-sale securities, short-term	$ 1,344	$ 1,046
Trading securities, short-term	0	0
Total short-term	1,344	1,046
Long-term
Available-for-sale securities, long-term	7,151	5,425
Trading securities, long-term	46	39
Total long-term	7,197	5,464
Credit Loss Portion of Other-than-temporary Impairments on Debt Securities
Beginning Balance	20	17
Credit losses recognized on securities previously not impaired	1	2
Additional credit losses recognized on securities previously impaired	1	3
Reductions for securities sold during the period	(2)	(2)
Ending Balance	20	20
AFS Debt Maturities
Due in one year or less	1,940
Due after one year through five years	5,374
Due after five years through ten years	796
Due after ten years	132
Total debt securities	$ 8,242