Condensed Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Oct. 26, 2012	Oct. 28, 2011	Oct. 26, 2012	Oct. 28, 2011
Other Comprehensive Income (Loss), Tax
Unrealized gain/(loss) on investments, tax expense/(benefit)	$ 1	$ (28)	$ 4	$ 28
Net change in retirement obligations, tax expense/(benefit)	6	6	19	12
Unrealized gain/(loss) on derivatives, tax expense/(benefit)	$ (36)	$ 42	$ (16)	$ 48