Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jan. 29, 2016	Jan. 23, 2015	Jan. 29, 2016	Jan. 23, 2015	Apr. 24, 2015
Income Tax Disclosure [Abstract]
Tax charge, primarily associated with internal reorganization of certain businesses	$ 25
Effective tax rate from continuing operations	7.10%	18.20%	24.00%	18.90%
Gross unrecognized tax benefits	$ 2,647		$ 2,647		$ 2,860
Accrued income tax interest and penalties	607		607
Unrecognized tax benefits that would impact effective tax rate	2,070		2,070
Gross unrecognized tax benefits, current liability	11		11
Gross unrecognized tax benefits, long-term liability	$ 2,636		$ 2,636