Investments, Marketable Securities, Credit Losses on and Maturities of Debt Securities (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Jul. 27, 2012	Jul. 29, 2011	Apr. 27, 2012
Short-term
Available-for-sale securities, short-term	$ 1,630		$ 1,344
Trading securities, short-term	0		0
Total short-term	1,630		1,344
Long-term
Available-for-sale securities, long-term	7,729		7,151
Trading securities, long-term	45		46
Total long-term	7,774		7,197
Credit Loss Portion of Other-than-temporary Impairments on Debt Securities
Beginning Balance	20	20
Credit losses recognized on securities previously not impaired	0	1
Reductions for securities sold during the period	0	(1)
Ending Balance	20	20
AFS Debt Maturities
Due in one year or less	2,302
Due after one year through five years	5,917
Due after five years through ten years	728
Due after ten years	144
Total debt securities	$ 9,091