Investments, Marketable Securities, Credit Losses on and Maturities of Debt Securities (Details) (USD $) In Millions, unless otherwise specified									3 Months Ended	6 Months Ended
	Oct. 24, 2014	Apr. 25, 2014	Oct. 24, 2014 Investments	Apr. 25, 2014 Investments	Oct. 24, 2014 Other Assets	Apr. 25, 2014 Other Assets	Oct. 24, 2014 Available for Sale Securities	Apr. 25, 2014 Available for Sale Securities	Oct. 24, 2014 Other Expense, Net	Oct. 24, 2014 Other Expense, Net
Long-term
Available-for-sale securities, fair value			$ 13,107	$ 12,771	$ 154	$ 155	$ 46	$ 49
Trading securities, fair value			70	67	0	0
Investments Other than Available-for-sale and Trading Securities			0	0	563	666
Investments	13,177	12,838
Long-term investments	717	821
Credit Loss Portion of Other-than-temporary Impairments on Debt Securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held	4	4
AFS Debt Maturities
Due in one year or less	1,714
Due after one year through five years	6,046
Due after five years through ten years	2,559
Due after ten years	154
Total debt securities	10,473
Impairment charges, marketable equity investments									$ 7	$ 7