Investments, Investments Portfolio and AFS Continuous Unrealized Loss Position (Details) (USD $) In Millions, unless otherwise specified																						3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Oct. 25, 2013	Apr. 26, 2013	Oct. 25, 2013 Corporate Debt Securities	Apr. 26, 2013 Corporate Debt Securities	Oct. 25, 2013 Auction Rate Securities	Apr. 26, 2013 Auction Rate Securities	Oct. 25, 2013 Mortgage Backed Securities	Apr. 26, 2013 Mortgage Backed Securities	Oct. 25, 2013 US Government and Agency Securities	Apr. 26, 2013 US Government and Agency Securities	Oct. 25, 2013 Foreign Government and Agency Securities	Apr. 26, 2013 Foreign Government and Agency Securities	Oct. 25, 2013 Certificates of Deposit	Apr. 26, 2013 Certificates of Deposit	Oct. 25, 2013 Other Asset-backed Securities	Apr. 26, 2013 Other Asset-backed Securities	Oct. 25, 2013 Debt Funds [Member]	Oct. 25, 2013 Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]	Apr. 26, 2013 Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]	Oct. 25, 2013 Exchange Traded Funds	Apr. 26, 2013 Exchange Traded Funds	Oct. 25, 2013 Debt Securities	Oct. 26, 2012 Debt Securities	Oct. 25, 2013 Debt Securities	Oct. 26, 2012 Debt Securities	Oct. 25, 2013 Equity Securities	Oct. 26, 2012 Equity Securities	Oct. 25, 2013 Equity Securities	Oct. 26, 2012 Equity Securities	Oct. 25, 2013 Nonrecurring	Apr. 26, 2013 Nonrecurring
Available-for-sale securities:
Available-for-sale securities, cost			$ 4,984	$ 4,587	$ 114	$ 118	$ 1,305	$ 1,050	$ 3,512	$ 3,882	$ 55	$ 38	$ 6	$ 6	$ 597	$ 539	$ 997	$ 63	$ 82
Available-for-sale securities, unrealized gains			48	78	0	0	8	8	8	17	0	0	0	0	2	2	27	43	75
Available-for-sale securities, unrealized losses			(23)	(4)	(9)	(15)	(8)	(5)	(38)	(1)	0	0	0	0	(1)	0	(7)	0	(2)
Available-for-sale securities, fair value			5,009	4,661	105	103	1,305	1,053	3,482	3,898	55	38	6	6	598	541	1,017	106	155
Trading securities:
Trading securities, cost																				50	45
Trading securities, unrealized gains																				10	5
Trading securities, unrealized losses																				0	0
Trading securities, fair value																				60	50
Aggregate carrying amount of investments in equity and other securities that are accounted for using the cost or equity method	629	549																												629	549
Short-term and long-term investments, cost	12,312	10,896
Short-term and long-term investments, unrealized gains	146	185
Short-term and long-term investments, unrealized losses	(86)	(27)
Short-term and long-term investments, fair value	11,743	10,505
AFS Continuous Unrealized Loss Position
Less than 12 months, fair value	3,970	1,044	1,629	544	0	0	642	195	1,326	291					215		158		14
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	73	5	20	1	0	0	7	1	38	1					1		7		2
More than 12 months, fair value	150	160	14	13	105	103	31	44	0	0					0		0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	13	22	3	3	9	15	1	4	0	0					0		0		0
AFS Gross Realized Gain (Loss)
Proceeds from sales																						2,072	4,019	4,235	5,890	24	41	56	65
Gross realized gains																						0	24	6	41	15	29	33	37
Gross realized losses																						(1)	(3)	(6)	(7)	0	0	0	0
Impairment losses recognized																						$ 0	$ 0	$ 0	$ 0	$ 0	$ (4)	$ 0	$ (10)