Fair Value Measurements (Unobservable Input Reconciliation) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Oct. 28, 2011	Oct. 29, 2010	Oct. 28, 2011	Oct. 29, 2010
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of	$ 190	$ 198	$ 191	$ 213
Total realized losses and other-than-temporary impairment losses included in earnings	(1)	(2)	(2)	(4)
Total unrealized gains/(losses) included in other comprehensive income	(7)	9	(5)	7
Settlements	(8)	(3)	(10)	(14)
Balance as of	174	202	174	202
Corporate Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of	17	16	17	16
Total realized losses and other-than-temporary impairment losses included in earnings	(1)	(1)	(1)	(2)
Total unrealized gains/(losses) included in other comprehensive income	1	2	1	4
Settlements	(7)	0	(7)	(1)
Balance as of	10	17	10	17
Auction Rate Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of	134	138	133	142
Total realized losses and other-than-temporary impairment losses included in earnings	0	0	0	0
Total unrealized gains/(losses) included in other comprehensive income	(7)	5	(6)	1
Settlements	0	0	0	0
Balance as of	127	143	127	143
Mortgage Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of	33	37	35	39
Total realized losses and other-than-temporary impairment losses included in earnings	0	(1)	0	(2)
Total unrealized gains/(losses) included in other comprehensive income	(1)	2	(1)	2
Settlements	(1)	(2)	(3)	(3)
Balance as of	31	36	31	36
Other Asset-backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of	6	7	6	16
Total realized losses and other-than-temporary impairment losses included in earnings	0	0	(1)	0
Total unrealized gains/(losses) included in other comprehensive income	0	0	1	0
Settlements	0	(1)	0	(10)
Balance as of	$ 6	$ 6	$ 6	$ 6