Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jan. 29, 2016	Jan. 23, 2015	Jan. 29, 2016	Jan. 23, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			$ (1,184)	$ (597)
Other comprehensive (loss) income before reclassifications, before tax			(1,776)	199
Tax benefit (expense)			93	(181)
Other comprehensive (loss) income before reclassifications, net of tax			(1,683)	18
Reclassifications, before tax			(160)	(127)
Tax benefit (expense)			62	45
Reclassifications, net of tax			(98)	(82)
Other comprehensive loss	$ (1,494)	$ (155)	(1,781)	(64)
Ending balance	(2,965)	(661)	(2,965)	(661)
Unrealized Gain (Loss) on Available-for-Sale Securities [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			14	(6)
Other comprehensive (loss) income before reclassifications, before tax			(399)	110
Tax benefit (expense)			143	(40)
Other comprehensive (loss) income before reclassifications, net of tax			(256)	70
Reclassifications, before tax			(18)	(134)
Tax benefit (expense)			6	47
Reclassifications, net of tax			(12)	(87)
Other comprehensive loss			(268)	(17)
Ending balance	(254)	(23)	(254)	(23)
Cumulative Translation Adjustments [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			(277)	218
Other comprehensive (loss) income before reclassifications, before tax			(1,513)	(332)
Tax benefit (expense)			0	0
Other comprehensive (loss) income before reclassifications, net of tax			(1,513)	(332)
Reclassifications, before tax			0	0
Tax benefit (expense)			0	0
Reclassifications, net of tax			0	0
Other comprehensive loss			(1,513)	(332)
Ending balance	(1,790)	(114)	(1,790)	(114)
Net Change in Retirement Obligations [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			(1,131)	(765)
Other comprehensive (loss) income before reclassifications, before tax			2	24
Tax benefit (expense)			0	0
Other comprehensive (loss) income before reclassifications, net of tax			2	24
Reclassifications, before tax			90	57
Tax benefit (expense)			(30)	(18)
Reclassifications, net of tax			60	39
Other comprehensive loss			62	63
Ending balance	(1,069)	(702)	(1,069)	(702)
Unrealized Gain (Loss) on Derivatives [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			210	(44)
Other comprehensive (loss) income before reclassifications, before tax			134	397
Tax benefit (expense)			(50)	(141)
Other comprehensive (loss) income before reclassifications, net of tax			84	256
Reclassifications, before tax			(232)	(50)
Tax benefit (expense)			86	16
Reclassifications, net of tax			(146)	(34)
Other comprehensive loss			(62)	222
Ending balance	$ 148	$ 178	$ 148	$ 178