Condensed Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Jan. 24, 2014	Jan. 25, 2013	Jan. 24, 2014	Jan. 25, 2013
Other Comprehensive Income (Loss), Tax
Unrealized gain/(loss) on investments, tax expense/(benefit)	$ (34)	$ (19)	$ (71)	$ (15)
Net change in retirement obligations, tax expense/(benefit)	8	7	25	26
Unrealized gain/(loss) on derivatives, tax expense/(benefit)	$ 27	$ (2)	$ (25)	$ (18)